U.S. patent number 6,288,157 [Application Number 09/309,836] was granted by the patent office on 2001-09-11 for alkylated fluorochemical oligomers and use thereof.
This patent grant is currently assigned to 3M Innovative Properties Company. Invention is credited to Rudolf J. Dams, Chetan P. Jariwala, Marvin E. Jones, Thomas P. Klun.
United States Patent |
6,288,157 |
Jariwala , et al. |
September 11, 2001 |
**Please see images for:
( Certificate of Correction ) ** |
Alkylated fluorochemical oligomers and use thereof
Abstract
This invention provides fluorochemical compounds comprising: a
fluorochemical oligomeric portion comprising an aliphatic backbone
with a plurality of pendant fluoroaliphatic groups, each
fluoroaliphatic group having a fully fluorinated terminal group and
each independently linked to a carbon atom of the aliphatic
backbone through an organic linking group; an aliphatic moiety; and
a linking group which links the fluorochemical oligomeric portion
to the aliphatic moiety. The fluorochemical compounds are useful as
topical treatments for fibrous substrates such as textiles and
fabrics, and as polymer melt additives to provide desirable oil-,
water and stain repellency to shaped articles such as fibers.
Inventors: |
Jariwala; Chetan P. (Woodbury,
MN), Klun; Thomas P. (Lakeland, MN), Dams; Rudolf J.
(Antwerp, BE), Jones; Marvin E. (Grant, MN) |
Assignee: |
3M Innovative Properties
Company (St. Paul, MN)
|
Family
ID: |
23199873 |
Appl.
No.: |
09/309,836 |
Filed: |
May 11, 1999 |
Current U.S.
Class: |
524/462; 524/463;
526/242; 526/250; 526/253; 526/254; 526/255 |
Current CPC
Class: |
C07C
323/52 (20130101); C14C 9/00 (20130101); D06M
13/236 (20130101); D06M 13/256 (20130101); D06M
13/265 (20130101); D06M 15/277 (20130101); D06M
15/53 (20130101); D06M 2200/11 (20130101); D06M
2200/12 (20130101) |
Current International
Class: |
C07C
323/00 (20060101); C07C 323/52 (20060101); C14C
9/00 (20060101); D06M 15/53 (20060101); D06M
15/277 (20060101); D06M 15/21 (20060101); D06M
15/37 (20060101); D06M 13/00 (20060101); D06M
13/265 (20060101); D06M 13/256 (20060101); D06M
13/236 (20060101); C08K 003/00 () |
Field of
Search: |
;526/242,250,253,254,255
;524/462,463 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
3041160 |
|
Feb 1991 |
|
JP |
|
9323956 |
|
Dec 1997 |
|
JP |
|
WO 92/15732 |
|
Sep 1992 |
|
WO |
|
WO 97/07272 |
|
Feb 1997 |
|
WO |
|
WO 97/22659 |
|
Jun 1997 |
|
WO |
|
WO 97/22660 |
|
Jun 1997 |
|
WO |
|
WO 97/22576 |
|
Jun 1997 |
|
WO |
|
WO 98/15598 |
|
Apr 1998 |
|
WO |
|
WO 98/51724 |
|
Nov 1998 |
|
WO |
|
WO 98/51725 |
|
Nov 1998 |
|
WO |
|
WO 98/51726 |
|
Nov 1998 |
|
WO |
|
WO 98/51727 |
|
Nov 1998 |
|
WO |
|
WO 98/51723 |
|
Nov 1998 |
|
WO |
|
WO 99/05345 |
|
Feb 1999 |
|
WO |
|
Other References
HC. Fielding, "Organofluorine Chemicals and Their Industrial
Applications", R.E. Banks, Ed., Society of Chemical Industry, 1979,
pp. 214-234. .
Chujo et al., J. Polymer Science, Part A, 1988, 26, 2991. .
Van Wente et al., "Manufacture of Super Fine Organic Fibers",
Report No. 4364 of the Naval Research Laboratories, May 25, 1954.
.
C.N. Davies, "The Separation of Airborne Dust and Particles",
Institution of Mechanical Engineers, London, Proceedings 1B, 1952.
.
Van Wente, "Superfine Thermoplastic Fibers", Industrial Engineering
Chemistry, vol. 48, 1956, pp. 1342-1346..
|
Primary Examiner: Cain; Edward J.
Attorney, Agent or Firm: Kokko; Kent S.
Claims
We claim:
1. Fluorochemical oligomeric compounds of the formula: ##STR5##
wherein
each L independently comprises a linking group;
R is a linear, monovalent alkyl group of 12 to 75 carbon atoms;
a is an integer such that A is oligomeric and comprises a plurality
of R.sub.f groups;
each R.sub.1 is independently a hydrogen, halogen, or straight
chain or branched chain alkyl containing 1 to about 4 carbon
atoms;
each R.sub.2 is independently hydrogen or straight chain or
branched chain alkyl containing 1 to about 4 carbon atoms;
each Q is a covalent bond or an organic linking group;
R.sub.f is a fluoroaliphatic group;
X is a hydrogen atom or a group derived from a free radical
initiator.
2. The compounds of claim 1 wherein a is 3 to 8.
3. The compounds of claim 2 wherein R.sub.f has the structure
C.sub.o F.sub.2o+1, where o is 4to 14.
4. The compounds of claim 1 wherein L is selected from the group of
a covalent bond, straight chain, branched chain, or cyclic
alkylene, arylene, aralkylene, oxy, oxo, hydroxy, thio, sulfonyl,
sulfoxy, amino, imino, sulfonamido, carboxamido, carbonyloxy,
urethanylene, ureylene, and combinations thereof.
5. The compounds of claim 4 wherein L is chosen from the group
consisting of
wherein each k is independently an integer from 0 to about 20, and
R.sub.2 ' is alkyl of 1 to about 20 carbon atoms.
6. The compounds of claim 2 comprising oligomerized units of
compounds of the formula ##STR6##
wherein R.sub.1, R.sub.2, R.sub.f and Q are as defined in claim
2.
7. A synthetic organic polymer composition comprising one or more
compounds of claim 2 and a synthetic organic polymer.
8. The polymer composition of claim 7 wherein the synthetic organic
polymer is a thermoplastic polymer.
9. The composition of claim 8 wherein said thermoplastic polymers
are selected from the group consisting of polyamides, polyesters,
polyurethanes, and polyolefins.
10. The composition of claim 7 wherein said compounds comprises
from 0.5 to 5 weight percent of said composition.
11. A shaped article comprising a melt-processible thermoplastic
polymer and the compounds of claim 1.
12. The shaped article of claim 11 wherein said compounds provide
from 100 to 10,000 ppm fluorine.
13. The shaped article of claim 11 selected from the group of
films, sheets and fibers.
14. An oily mist resistant electret filter medium comprising
polypropylene electret fibers and the compounds of claim 1.
15. The filter medium of claim 14 wherein said fibers have an
effective fiber diameter of 2 to 30 micrometers.
16. The filter medium of claim 14 wherein said fibers have been
annealed.
17. The filter medium of claim 14 wherein said filter media has a
basis weight of 10 to 100 g/m.sup.2.
18. The compounds of claim 1 wherein Q is selected from the group
consisting of
wherein each k is independently an integer from 0 to about 20,
R.sub.1 ' is hydrogen, phenyl, or alkyl of 1 to about 4 carbon
atoms, and R.sub.2 ' is alkyl of 1 to about 20 carbon atoms.
19. The composition of claim 7 wherein the synthetic organic
polymer is a thermoset polymer.
20. The composition of claim 19 wherein said thermoset polymer is
selected from the group consisting of epoxy resins, urethanes and
acrylates.
21. The compounds of claim 1 wherein R is an alkyl group of 18 to
60 carbon atoms,
a version marked up to show changes made to the claim(s) relative
to the previous version of the claim(s) is attached.
Description
This invention relates to fluorochemical compositions for use in
providing repellent properties to a substrate material. In another
aspect, this invention relates to fluorochemical compounds that
contain pendent fluoroaliphatic groups proximal to one another. In
yet another aspect, it relates to fluorochemical compounds that are
at least in part oligomeric in nature. This invention also relates
to thermoplastic compositions comprising the fluorochemical
composition and shaped articles made from the thermoplastic
composition.
The utility of organofluorine compounds as surface-active agents
(i.e., surfactants) and surface-treating agents is due in large
part to the extremely low free-surface energy of a C.sub.6
-C.sub.12 fluorocarbon group, according to H. C. Fielding,
"Organofluorine Compounds and Their Applications," R. E. Banks,
Ed., Society of Chemical Industry at p. 214 (1979). Generally, the
organofluorine substances described above are those which have
carbon-bonded fluorine in the form of a monovalent fluoroaliphatic
radical such as a perfluoroalkyl group, typically --C.sub.n
F.sub.2n+1 where n is at least 3, the terminal part of which group
is trifluoromethyl, --CF.sub.3.
U.S. Pat. No. 3,758,447 (Falk et al.) describes polymers that
result from free radical polymerization of a monomer in the
presence of perfluoroalkyl mercaptans, which act as chain-transfer
agents. Mercaptans that contain pairs or triplets of closely-packed
perfluoroalkyl groups are said to produce polymers with higher oil
repellency levels compared with analogous polymers derived from a
mercaptan with just one perfluoroalkyl group or perfluoroalkyl
groups that are not closely packed.
U.S. Pat. No. 5,453,540 (Dams et al.) describes fluorochemical
compositions for the treatment of textiles comprising: (i) a
fluorochemical oligomeric portion comprising an aliphatic backbone
with a plurality of fluoroaliphatic groups attached thereto, each
fluoroaliphatic group having a fully fluorinated terminal group and
each independently linked to a carbon atom of the aliphatic
backbone through an organic linking group;(ii) an organic moiety
(which can be functional or non-functional, and which is different
from the fluorochemical oligomeric portion); (iii) a non-polymeric
isocyanate-derived linking group which links the fluorochemical
oligomeric portion to the organic moiety; and
(iv) a group bonded thereto, which can impart soft hand, stain
release, water repellency, or a durable property when the compound
is applied to a fibrous substrate.
J. Polymer Science, Part A 1988, 26, 2991 (Chujo et al.) describes
a di-carboxyl terminated macromonomer prepared by the free radical
co-polymerization of a perfluoroalkylethyl acrylate and methyl
methacrylate in the presence of thiomalic acid. Also described is
the reaction of such macromonomers with organic dicarboxylic acids
and organic diamines in the presence of an appropriate catalyst to
afford a copolymer wherein the macromonomer is grafted onto a
polyamide chain.
Several patents have taught that the addition of certain
fluorochemicals to thermoplastic impart oil and stain repellency to
thermoplastic articles such as fibers. For example U.S. Pat. No.
5,025,052 (Crater et al.) describes the use of fluoroaliphatic
radical-containing 2-oxazolidinone compounds having a monovalent
fluoroaliphatic radical bonded to the 5-position thereof with an
organic linking group. The compounds are said to be useful in the
surface treatment of fibrous materials, such as textiles and are
also useful in preparing fibers, films and molded articles by
melt-extrusion or injection molding. U.S. Pat. No. 5,380,778
(Buckanin) describes the use of fluorochemical aminoalcohols in
thermoplastic compositions which can be melted and shaped, for
example by extrusion or molding, to provide fibers and films having
desirable oil- and water-repellency properties. U.S. Pat. No.
5,451,622 (Boardman et al.) describes shaped articles, such as
fibers and films, made by melt extruding mixtures of fluorochemical
piperazine compounds and a thermoplastic polymer. U.S. Pat. No.
5,411,576 (Jones et al.) describes an oily mist resistant electret
filter medium comprising melt-blown electret microfibers and a
melt-processible fluorochemical having a melting point of at least
about 25.degree. C. and a molecular weight of about 500 to 2500,
the fluorochemical being a fluorochemical piperazine, oxazolidinone
or perfluorinated alkane having from 15 to 50 carbon atoms. U.S.
Pat. No. 5,300,587 (Macia et al.) describes oil-repellent polymeric
compositions made by blending a perfluoropolyether and a
thermoplastic polymer. U.S. Pat. No. 5,336,717 (Rolando et al.)
discloses fluorochemical graft copolymers derived from reacting
monomers having termianl olefinic bonds with fluorochemical olefins
having fluoroaliphatic groups and polymerizable double bonds.
While these fluorochemical melt additives can in some circumstances
impart satisfactory hydrophobicity and/or oleophobicity to
thermoplastic resins they typically suffer from poor thermal
stability above 300.degree. C., a melt processing temperature often
encountered in the industry, and they can also be prohibitively
expensive, lending limitations to their commercial utility.
For many years nonwoven fibrous filter webs have been made from
polypropylene using melt-blowing apparatus of the type described in
Report No. 4364 of the Naval Research Laboratories, published May
25, 1954, entitled "Manufacture of Super Fine Organic Fibers" by
Van Wente et al. Such melt-blown microfiber webs continue to be in
widespread use for filtering particulate contaminants, e.g., as
face masks and as water filters, and for other purposes, e.g., to
remove oil from water.
Fibrous filters for removing particulate contaminants from the air
are also made from fibrillated polypropylene films. Electret
filtration enhancement can be provided by electrostatically
charging the film before it is fibrillated. Common polymers such as
polyesters, polycarbonates, etc. can be treated to produce highly
charged electrets but these charges are usually short-lived
especially under humid conditions. The electret structures may be
films or sheets which find applications as the electrostatic
element in electro-acoustic devices such as microphones, headphones
and speakers and in dust particle control, high voltage
electrostatic generators, electrostatic recorders and other
applications.
Fibrous polypropylene electret filters that are currently
available, some made from melt-blown polypropylene microfibers and
others from fibrillated polypropylene film, can show thermally
stable electret filtration enhancement. Unfortunately, fibrous
electret filters made of polypropylene, whether melt-blown
microfibers or fibrillated film, tend to lose their electret
enhanced filtration efficiency faster than desired for some
purposes when exposed to oily aerosols. There is a growing
awareness of the need to improve the long-term efficiency of air
filters in the presence of aerosol oils, especially in respirators.
It is known to blend about 1 to 20 weight percent
poly(4-methyl-1-pentene) with polypropylene to provide resistance
to loss of electret enhanced filtration efficiency on exposure to
oily aerosols.
SUMMARY OF THE INVENTION
This invention provides fluorochemical compounds comprising:
(i) a fluorochemical oligomeric portion comprising an aliphatic
backbone with a plurality of pendant fluoroaliphatic groups, each
fluoroaliphatic group having a fully fluorinated terminal group and
each independently linked to a carbon atom of the aliphatic
backbone through an organic linking group;
(ii) an aliphatic moiety; and
(iii) a linking group which links the fluorochemical oligomeric
portion to the aliphatic moiety.
In another aspect, the present invention provides a fluorochemical
composition comprising at least one fluorochemical compound
described above.
In another aspect, the present invention provides a synthetic
organic polymer composition comprising the alkylated fluorochemical
oligomer described above and a thermoplastic or thermoset synthetic
organic polymer, such as a polyamide, polyurethane, polyester,
epoxide or polyolefin. The thermoplastic composition can be melted
and shaped, for example by extrusion or molding, to produce shaped
articles, such as fibers or films. Said compounds impart desirable
oil- and water repellencies to the surfaces of such shaped articles
such as films, sheets, fibers and molded articles. The composition
is especially useful in the preparation of nonwoven fabrics used in
medical gowns, drapes and masks to provided the necessary
repellency to bodily fluids. Films containing fluorochemical
oligomeric compounds of this invention are useful, for example, for
moisture and/or grease-resistant packaging, release liners, and
multilayer constructions.
In another aspect, the present invention provides oily mist
resistant electret filter medium comprising polypropylene electret
fibers and the alkylated fluorochemical oligomer composition
described above as a melt processible additive, said additive
having a melting temperature of at least 25 deg. C. Preferably the
fibers may be in the form of meltblown microfibers.
In another aspect, the present invention provides a method for
filtering particulate material from air containing oily aerosol
particles comprising passing said air through electret filter media
comprising polypropylene melt blown microfibers and a melt
processable fluorochemical additive. The electret filter medium of
the present invention have improved electret filtration enhancement
and sustain that enhancement upon exposure to oily aerosols.
Furthermore, the electret filter media of the present invention
maintain functional filtration enhancing charge levels under
accelerated aging conditions.
The novel fibrous electret filter media are especially useful as an
air filter element of a respirator such as a face mask or for such
purposes as heating, ventilation, and air-conditioning. In
respirator uses, the novel electret filter media may be in the form
of molded or folded half-face masks, replaceable cartridges or
canisters, or prefilters. In such uses, an air filter element of
the invention is surprisingly effective for removing oily aerosols
such as are present in cigarette smoke or in fumes from combustion
engines. When used as an air filter medium, such as in a
respirator, the electret filter medium has surprisingly better
filtration performance than does a comparable electret filter media
made of 100% polypropylene fibers.
DETAILED DESCRIPTION
The alkylated fluorochemical oligomers in a composition of the
invention generally contain a plurality of pendant fluoroaliphatic
groups proximal to one another (e.g., located on alternating carbon
atoms of an aliphatic backbone, or occasionally on adjacent carbon
atoms), as distinct from isolated fluoroaliphatic groups randomly
distributed throughout the compound and also as distinct from
fluoroaliphatic groups uniformly located on adjacent carbon
atoms.
In other preferred embodiments, the invention provides
fluorochemical compositions comprising fluorinated compounds of
Formulas I or II
[(A).sub.m - L].sub.n R I (A).sub.m [L - R].sub.n II
wherein
m is 1 or 2;
n is 1 to 4 inclusive;
each L independently comprises a linking group;
R is a saturated or unsaturated aliphatic moiety of 1 to 75 carbon
atoms; and
A is a fluorochemical oligomeric portion of the formula:
##STR1##
wherein
a is an number such that A is oligomeric and comprises a plurality
of pendent R.sub.f groups;
R.sub.1 is hydrogen, halogen, or straight chain or branched chain
alkyl containing 1 to about 4 carbon atoms;
each R.sub.2 is independently hydrogen or straight chain or
branched chain alkyl containing 1 to about 4 carbon atoms;
each Q is a covalent bond or an organic linking group, such as a
sulfonamidoalkylene group;
R.sub.f is a fluoroaliphatic group, such as --(CF.sub.2).sub.7
CF.sub.3, that comprises a fully fluorinated terminal group;
X is a hydrogen atom or a group derived from a free radical
initiator (e.g. t-butoxy).
Preferably, with reference to Formulas I and II, both m and n are
one to produce an alkylated oligomeric fluorochemical of the
Formula IV: ##STR2##
As described above and further illustrated in Formulas I-IV, a
fluorochemical composition of the invention comprises an alkylated
fluorochemical oligomeric compound that generally has three
principal portions: a fluorochemical oligomeric portion "A", a
linking group "L", and an aliphatic moiety "R". The fluorochemical
oligomeric portion and the organic moiety are linked together by
linking group L. The linking group may be a covalent bond, may
result from a condensation reaction between a nucleophile, such as
an alcohol, an amine, or a thiol, and an electrophile such as a
carboxylic acid, ester, acyl halide, sulfonate ester, sulfonyl
halide, cyanate, isocyanate, or may result from a nucleophilic
displacement reaction between a nucleophile, such as previously
described, and a moiety bearing a leaving group, such as the
reaction between an alcohol (or alkoxide) and an alkyl halide
(where the halogen atom of the alkyl halide serves as a leaving
group).
Examples of suitable linking groups L include a covalent bond,
straight chain, branched chain, or cyclic alkylene, arylene,
aralkylene, oxy, oxo, hydroxy, thio, sulfonyl, sulfoxy, amino,
imino, sulfonamido, carboxamido, carbonyloxy, urethanylene,
ureylene, and combinations thereof such as sulfonamidoalkylene.
A salient component of the fluorochemical oligomeric portion is the
fluoroaliphatic group, designated herein as R.sub.f. The
fluorinated compound of the invention contains a plurality of
pendent R.sub.f groups (e.g., from 2 to about 10) proximal to one
another and preferably contains from about 5 percent to about 80
percent, more preferably from about 20 percent to about 65 percent,
and most preferably about 25 percent to about 55 percent fluorine
by weight, based on the total weight of the compound, the loci of
the fluorine being essentially in the R.sub.f groups. R.sub.f is a
stable, inert, non-polar, preferably saturated, monovalent moiety
which is both oleophobic and hydrophobic. R.sub.f preferably
contains at least about 3 carbon atoms, more preferably 3 to about
20 carbon atoms, and most preferably about 4 to about 14 carbon
atoms. R.sub.f can contain straight chain, branched chain, or
cyclic fluorinated alkylene groups or combinations thereof or
combinations thereof with straight chain, branched chain, or cyclic
alkylene groups. R.sub.f is preferably free of polymerizable
olefinic unsaturation and can optionally contain catenary
heteroatoms such as divalent oxygen, or trivalent nitrogen. It is
preferred that R.sub.f contain about 35% to about 78% fluorine by
weight, more preferably about 40% to about 78% fluorine by weight.
The terminal portion of the R.sub.f group contains a fully
fluorinated terminal group. This terminal group preferably contains
at least 7 fluorine atoms, e.g., CF.sub.3 CF.sub.2 CF.sub.2 --,
(CF.sub.3).sub.2 CF--, or the like. Perfluorinated aliphatic groups
(i.e., those of the formula C.sub.o F.sub.2o+1, where o is 4 to 14
are the most preferred embodiments of R.sub.f.
The aliphatic backbone of the fluorochemical oligomeric portion
comprises a sufficient number of polymerized units to render the
portion oligomeric. The aliphatic backbone preferably comprises
from 2 to about 10 polymerized units ("a" in Formula IV) derived
from fluorinated monomers (i.e., monomers containing a fluorinated
organic group R.sub.f as defined above), it is more preferred that
the aliphatic backbone comprise from 3 to about 8, most preferably
about 4, polymerized units.
The fluorochemical compositions of the invention generally comprise
mixtures of alkylated fluorochemical oligomeric compounds.
Accordingly, compounds are sometimes referred to herein as having
non-integral numbers of particular substituents (e.g., "a=2.7"). In
such cases the number indicates an average and is not intended to
denote fractional incorporation of a substituent. The terms
"oligomer" or "oligomeric" when used herein designate compounds
containing a plurality of polymerized units, but fewer than that
number of polymerized units present in a polymer (e.g., chains of 2
to about 10 polymerized units are to be considered
"oligomeric").
The fluoroaliphatic group R.sub.f is linked to the organic portion
(i.e. the oligomeric backbone or the unsaturated portion of the
monomer) by a linking group designated as Q in the formulas used
herein. Q is a linking group that is a covalent bond, divalent
alkylene, or a group that can result from the condensation reaction
of a nucleophile such as an alcohol, an amine, or a thiol with an
electrophile, such as an ester, acid halide, isocyanate, sulfonyl
halide, sulfonyl ester, or may result from a displacement reaction
between a nucleophile and leaving group. Each Q is independently
chosen, preferably contains from 1 to about 20 carbon atoms and can
optionally contain catenary oxygen, nitrogen, sulfur, or
silicon-containing groups or a combination thereof. Q is preferably
free of functional groups that substantially interfere with
free-radical oligomerization (e.g., polymerizable olefinic double
bonds, thiols, easily abstracted hydrogen atoms such as cumyl
hydrogens, and other such functionality known to those skilled in
the art). Examples of suitable linking groups Q include straight
chain, branched chain, or cyclic alkylene, arylene, aralkylene;
oxy, oxo, hydroxy, thio, sulfonyl, sulfoxy, amino, imino,
sulfonamido, carboxamido, carbonyloxy, urethanylene, ureylene, and
combinations and multiples thereof such as sulfonamidoalkylene or
polyoxyalkylene. Preferably linking group Q is a covalent bond or a
sulfonamidoalkylene group.
Suitable linking groups Q include the following structures in
addition to a covalent bond. For the purposes of this list, each k
is independently an integer from 0 to about 20, R.sub.1 ' is
hydrogen, phenyl, or alkyl of 1 to about 4 carbon atoms, and
R.sub.2 ' is alkyl of 1 to about 20 carbon atoms. Each structure is
non-directional, i.e. --(CH.sub.2).sub.k C(O)O-- is equivalent to
--O(O)C(CH.sub.2).sub.k --.
--SO.sub.2 NR.sub.1 '(CH.sub.2).sub.k O(O)C-- --CONR.sub.1
'(CH.sub.2).sub.k O(O)C-- --(CH.sub.2).sub.k O(O)C-- --CH.sub.2
CH(OR.sub.2 ')CH.sub.2 O(O)C-- --(CH.sub.2).sub.k C(O)O--
--(CH.sub.2).sub.k SC(O)-- --(CH.sub.2).sub.k O(CH.sub.2).sub.k
O(O)C-- --(CH.sub.2).sub.k S(CH.sub.2).sub.k O(O)C--
--(CH.sub.2).sub.k SO.sub.2 (CH.sub.2).sub.k O(O)C--
--(CH.sub.2).sub.k S(CH.sub.2).sub.k OC(O)-- --(CH.sub.2).sub.k
SO.sub.2 NR.sub.1 '(CH.sub.2).sub.k O(O)C-- --(CH.sub.2).sub.k
SO.sub.2 -- --SO.sub.2 NR.sub.1 '(CH.sub.2).sub.k O-- --SO.sub.2
NR.sub.1 '(CH.sub.2).sub.k -- --(CH.sub.2).sub.k O(CH.sub.2).sub.k
C(O)O-- --(CH.sub.2).sub.k SO.sub.2 NR.sub.1 '(CH.sub.2).sub.k
C(O)O-- --(CH.sub.2).sub.k SO.sub.2 (CH.sub.2).sub.k C(O)O--
--CONR.sub.1 '(CH.sub.2).sub.k C(O)O-- --(CH.sub.2).sub.k
S(CH.sub.2).sub.k C(O)O-- --CH.sub.2 CH(OR.sub.2 ')CH.sub.2 C(O)O--
--SO.sub.2 NR.sub.1 '(CH.sub.2).sub.k C(O)O-- --(CH.sub.2).sub.k
O-- --(CH.sub.2).sub.k NR.sub.1 'C(O)O-- --OC(O)NR'(CH.sub.2).sub.k
--
The organic aliphatic moiety, designated R in compounds of Formulas
I-IV is a mono-, di-, tri- or tetravalent, linear or branched
chain, saturated or unsaturated, cyclic or acyclic (or any
combination thereof) organic aliphatic group having from 1 to 75
carbon atoms. In certain embodiments R may be fluorinated (i.e.
R=R.sub.f). The valency is equivalent to the value of n in Formula
I and is equal to 1 in Formula II. The range of structures
contemplated for the organic moiety R will be better understood
with reference to the compounds suitable for use in steps of the
Reaction Schemes described in detail below. Preferably R is a
linear, monovalent alkyl group having from 1 to 75 carbon atoms,
preferably 12 to 75 carbon atoms, and most preferably 18 to 60
carbon atoms. Where more than one R group is present, such as in
Formula II, or when n is greater than one in Formula I, the sum of
the carbon atoms in the R groups is preferably 100 carbon atoms or
fewer.
The fluorinated compounds and fluorochemical compositions of the
invention will be illustrated with reference to the embodiments
shown in Formulas I-IV. In such embodiments, linking group L links
the fluorochemical oligomeric portion A to the aliphatic group R.
Each linking group L may be a covalent bond, a di- or polyvalent
alkylene group, or a group that can result from the condensation
reaction of a nucleophile such as an alcohol, an amine, or a thiol
with an electrophile, such as an ester, acid halide, isocyanate,
sulfonyl halide, sulfonyl ester, or may result from a displacement
reaction between a nucleophile and leaving group. Each L is
independently chosen, preferably contains from 1 to about 20 carbon
atoms and can optionally contain catenary (i.e. in-chain) oxygen,
nitrogen, sulfur, or silicon-containing groups or a combination
thereof. L is preferably free of functional groups that
substantially interfere with free-radical oligomerization (e.g.,
polymerizable olefinic double bonds, thiols, easily abstracted
hydrogen atoms such as cumyl hydrogens, and other such detrimental
functionalities known to those skilled in the art). Examples of
suitable linking groups L include straight chain, branched chain,
or cyclic alkylene, arylene, aralkylene, oxy, oxo, sulfonyl,
sulfoxy, amino, imino, sulfonamido, carboxamido, carbonyloxy,
urethanylene, ureylene, and combinations thereof such as
sulfonamidoalkylene. Preferred L groups include the following
structures (including combinations and multiples thereof) wherein
each k is independently an integer from 0 to about 20, R.sub.2 ' is
alkyl of 1 to about 20 carbon atoms.
--(CH.sub.2).sub.k O(O)C-- --CH.sub.2 CH(OR.sub.2 ')CH.sub.2
C(O)O-- --(CH.sub.2).sub.k C(O)O-- --(CH.sub.2).sub.k O-- and
--(CH.sub.2).sub.k O(CH.sub.2).sub.k O(O)C--
Returning now to Formulas I-IV above, R.sub.1 is hydrogen, halogen
(e.g., fluoro, chloro, bromo), or straight chain or branched chain
alkyl of 1 to about 4 carbon atoms (e.g., methyl, ethyl, propyl,
isopropyl, butyl, isobutyl, and the like). Each R.sub.2 is
independently hydrogen or straight chain or branched chain alkyl of
1 to about 4 carbon atoms.
X is a group derived from a free-radical initiator. As used herein,
the term "free-radical initiator" designates any of the
conventional compounds such as organic azo compounds, organic
peroxides (e.g., diacyl peroxides, peroxyesters, dialkyl peroxides)
and the like that provide initiating radicals upon homolysis. As
used herein, the term "group derived from a free-radical initiator"
designates an initiating radical formed upon homolytic
decomposition of a free-radical initiator.
Suitable groups X include non-reactive groups such as a hydrogen
atom, t-butoxy (derived from di-t-butylperoxide), and benzoyloxy
(derived from benzoyl peroxide), and reactive groups such as
--CCH.sub.3 (CN)CH.sub.2 CH.sub.2 CO.sub.2 H (derived from
azo-4-cyanoisovaleric acid), --C(CH.sub.3).sub.2 CN (derived from
azoisobutyronitrile), and those derived from other known functional
azo compounds such as 2,2'-azobis[N-(4-chlorophenyl)
-2-methylpropionamidine]-dihydrochloride;
2,2'-azobis[N-(4-hydroxyphenyl)
-2-methylpropionamidine]dihydrochloride;
2,2,-azobis[N-(4-aminophenyl)
-2-methylpropionamidine]-tetrahydrochloride; 2,2'-azobis[2-methyl
-N-2-propenylpropionamidine]dihydrochloride;
2,2'-azobis[N-(2-hydroxyethyl)
-2-methylpropionamidine]-dihydrochloride;
2,2'-azobis[2-methyl-N-(2-hydroxyethyl) -propionamide];
2,2'-azobis[2-(hydroxymethyl)propionitrile];
2,2'-azobis[2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide
]; and
2,2'-azobis{2-methyl-N-[1,1-bis(hydroxymethyl)ethyl]-propionamide}.
Preferred groups X include those enumerated above.
The fluorochemical compounds of Formulas I, II and IV can be
prepared by oligomerization of an unsaturated, fluorinated compound
(V) in the presence of a free-radical initiator and chain-transfer
agent of the formula L(SH).sub.m (m=1-2) according to the following
Scheme: ##STR3##
The moiety "L" corresponds to the linking group moiety L of Formula
I, II and IV.
When the chain-transfer agent contains more than one sulfhydryl
group, multiple fluoroaliphatic groups A may be linked through
linking group L to one or more aliphatic R groups. For examples,
when the chain transfer agent contains two sulfhydryl groups, two
fluoroaliphatic groups A may be linked to L as follows:
Scheme 2 ##STR4##
Compounds of Formula (V) and methods for the preparation thereof
are known and disclosed, e.g., in U.S. Pat. Nos. 2,803,615
(Ahlbrecht et al.) and 2,841,573 (Ahlbrecht et al.) which
disclosures are incorporated herein by reference. Examples of such
compounds include general classes of fluorochemical monomers such
as acrylates, methacrylates, vinyl ethers, and allyl compounds
containing fluorinated sulfonamido groups, acrylates or
methacrylates derived from fluorochemical telomer alcohols,
fluorochemical thiols, and the like. Preferred compounds of Formula
V include N-methyl perfluorooctanesulfonamidoethyl acrylate,
N-methyl perfluorooctanesulfonamidoethyl methacrylate, N-ethyl
perfluorooctanesulfonamidoethyl acrylate, N-ethyl
perfluorohexylsulfonamidoethyl methacrylate, the reaction product
of isocyanatoethyl methacrylate and
N-methylperfluorooctanesulfonamidoethyl alcohol,
1,1-dihydroperfluorooctyl acrylate, N-methyl
perfluorooctanesulfonamidoethyl vinyl ether, C.sub.8 F.sub.17
SO.sub.2 NHCH.sub.2 CH.dbd.CH.sub.2, and others such as
perfluorocyclohexyl acrylate (c-C.sub.6 F.sub.11 CH.sub.2
OCOCH.dbd.CH.sub.2), and tetrameric hexafluoropropyleneoxide
dihydroacrylate.
When the chain transfer agent L(SH).sub.m bears a functional group,
a compound of Formula VI (Scheme I) is further reacted with a
functional aliphatic compound to form the linking group L and
incorporate the R group into the compounds of Formulas I, II and
IV. The nature of the functional groups on both the chain transfer
agent and the aliphatic compounds are chosen so that they are
reactive toward one another to form the L linking group. Examples
of mutually reactive pairs include an acyl group (such as a
carboxylic acid, acyl halide or ester) reacting with an alcohol or
amine, an alcohol or an amine reacting with a "leaving group" such
as a halide or tosylate, and an isocyanate reacting with an alcohol
or amine.
A compound of Formulas VI or VII can be provided with functional
groups on the L linking group (in addition to the sulfhydryl
group(s)) through the use of an appropriate functionalized
chain-transfer agent L(SH).sub.m, wherein L contains a functional
group. Suitable functional groups for inclusion in the
chain-transfer agent include hydroxy, amino, halo, epoxy,
haloformyl, aziridinyl, acid groups and salts thereof, which react
with an electrophile or nucleophile, or are capable of further
transformation into such groups. The use of a functionalized
chain-transfer agent allows for subsequent incorporation of the "R"
group of Formulas I and II. For example, the "L" group of the chain
transfer agent may be substituted with an electrophilic ester
moiety. This ester moiety will allow incorporation of a long chain
"R" group by further reaction with an aliphatic alcohol having a
nucleophilic hydroxyl group. Reaction between the two moieties
produces an ester linkage, thereby linking the fluorochemical
oligomeric moiety A with the aliphatic moiety R. Alternatively, for
example, the L moiety may be substituted with a hydroxyl group that
may be reacted with an aliphatic ester to link the fluorochemical
oligomeric moiety A with the aliphatic moiety R.
Examples of such functionalized chain transfer agents include
2-mercaptoethanol, mercaptoacetic acid, 2-mercaptobenzimidazole,
2-mercaptobenzoic acid, 2-mercaptobenzothiazole,
2-mercaptobenzoxazole, 3-mercapto-2-butanol, 2-mercaptosulfonic
acid, 2-mercaptonicotinic acid,
4-hydroxythiopheno3-mercapto-1,2-propanediol,
1-mercapto-2-propanol, 2-mercaptopropionic acid,
N-(2-mercaptopropionyl)glycine, 3-mercaptopropyltrimethoxysilane,
2-mercaptopyridine, 2-mercaptopyridine-N-oxide,
2-mercaptopyridinol, mercaptosuccinic acid,
2,3-mercaptopropanesulfonic acid, 2,3-dimercaptopropanol,
2,3-dimercaptosuccinic acid, cystine, cystine hydrochloride,
cystine ethylester. Preferred functionalized chain-transfer agents
include 2-mercaptoethanol, 3-mercapto-1,2-propanediol,
4-mercaptobutanol, 11-mercaptoundecanol, mercaptoacetic acid,
3-mercaptopropionic acid, 12-mercaptododecanoic acid,
2-mercaptoethylamine, 1-chloro-6-mercapto-4-oxahexan-2-ol,
2,3-dimercaptosuccinic acid, 2,3-dimercaptopropanol,
3-mercaptopropyltrimethoxysilane, 2-chloroethanethiol,
2-amino-3-mercaptopropionic acid, and compounds such as the adduct
of 2-mercaptoethylamine and caprolactam.
Advantageously, the R group of Formulas II, IV and IV may be
incorporated by use of a non-functional chain transfer agents.
Non-functionalized chain-transfer agents are those that contain a
group capable of terminating a radical chain reaction (e.g., a
sulfhydryl) but no further functional groups capable of reacting
with nucleophiles, electrophiles, or capable of undergoing
displacement reactions. In such cases, the aliphatic portion of
L(SH).sub.n provides the aliphatic group R of Formulas I and II.
Such compounds include mono, di, and polythiols such as
ethanethiol, propanethiol, butanethiol, hexanethiol, n-octylthiol,
t-dodecylthiol, 2-mercaptoethyl ether, 2-mercaptoimidazole,
2-mercaptoethylsulfide, 2-mercaptoimidazole, 8-mercaptomenthone,
2,5-dimercapto-1,3,4-thiadiazole, 3,4-toluenedithiol, o-, m-, and
p-thiocresol, ethylcyclohexanedithiol, p-menthane-2,9-dithiol,
1,2-ethanedithiol, 2-mercaptopyrimidine, and the like. Longer chain
alkyl thiols having 12 to 75 carbon atoms being preferred.
Whether functionalized or not, a chain transfer agent is present in
an amount sufficient to control the number of polymerized monomer
units in the oligomer. The end-capping agent is generally used in
an amount of about 0.05 to about 0.5 equivalents, preferably about
0.25 equivalents, per equivalent of olefinic monomer IV.
Also present in oligomerization process is a free-radical initiator
as defined above in connection with X. Such compounds are known to
those skilled in the art and include persulfates, azo compounds
such as azoisobutyronitrile and azo-2-cyanovaleric acid and the
like, hydroperoxides such as cumene, t-butyl, and t-amyl
hydroperoxide, dialkyl peroxides such as di-t-butyl and dicumyl
peroxide, peroxyesters such as t-butyl perbenzoate and
di-t-butylperoxy phthalate, diacylperoxides such as benzoyl
peroxide and lauroyl peroxide.
The initiating radical formed by an initiator can be incorporated
into the fluorochemical oligomer to varying degrees depending on
the type and amount of initiator used. A suitable amount of
initiator depends on the particular initiator and other reactants
being used. About 0.1 percent to about 5 percent, preferably about
0.1 percent, to about 0.8 percent, and most preferably about 0.2
percent to 0.5 percent by weight of an initiator can be used, based
on the total weight of all other reactants in the reaction.
The oligomerization reaction of Schemes 1 and 2 can be carried out
in any solvent suitable for organic free-radical reactions. The
reactants can be present in the solvent at any suitable
concentration, e.g., from about 5 percent to about 90 percent by
weight based on the total weight of the reaction mixture. Examples
of suitable solvents include aliphatic and alicyclic hydrocarbons
(e.g., hexane, heptane, cyclohexane), aromatic solvents (e.g.,
benzene, toluene, xylene), ethers (e.g., diethylether, glyme,
diglyme, diisopropyl ether), esters (e.g., ethyl acetate, butyl
acetate), alcohols (e.g., ethanol, isopropyl alcohol), ketones
(e.g., acetone, methyl ethyl ketone, methyl isobutyl ketone),
sulfoxides (e.g., dimethyl sulfoxide), amides (e.g.,
N,N-dimethylformamide, N,N-dimethylacetamide), halogenated solvents
such as methylchloroform, FREON.TM. 113, trichloroethylene,
.alpha.,.alpha.,.alpha.. -trifluorotoluene, fluorinated ethers such
as C.sub.4 F.sub.9 OCH.sub.3 and the like, and mixtures thereof
The oligomerization can be carried out at any temperature suitable
for conducting an organic free-radical reaction. Particular
temperature and solvents for use can be easily selected by those
skilled in the art based on considerations such as the solubility
of reagents, the temperature required for the use of a particular
initiator, and the like. While it is not practical to enumerate a
particular temperature suitable for all initiators and all
solvents, generally suitable temperatures are between about 30 deg.
C. and about 200 deg. C.
The alkylated fluorochemical oligomeric compounds of the present
invention may be used as additives that can provide oil and water
repellency to fibers. The fluorochemical additives are melt
processible, i.e., suffer substantially no degradation under the
melt processing conditions used to form the fibers. The
fluorochemical additive preferably has a molecular weight in the
range of about 1000 to 10,000, more preferably in the range of
about 1500 to 5000. When used in an electret filter medium, the
fluorochemical additive is preferably substantially free from
mobile polar and/or ionic species, contaminants and impurities
which could increase the electrical conductivity or otherwise
interfere with the ability of the fibers to accept and hold
electrostatic charges.
The present invention provides a synthetic organic polymer
composition comprising one or more of the fluorinated compounds of
the invention and a melt-processible synthetic organic polymer. The
compounds of the invention are useful as polymer melt additives to
impart desirable low surface energy properties to the
melt-processible polymer. Useful polymers include both
thermoplastic and thermoset polymers and include synthetic linear
polyamides, e.g., nylon-6 and nylon-66, polyesters, e.g.,
polyethylene terephthalate, polyurethanes, epoxides, acrylics,
polystyrenes and polyolefins, e.g., polyethylene and polypropylene.
Thermoplastic polymers such as polyolefins are preferred. The
resultant articles, due to the presence of the fluorochemical
additive, have improved oil- and water-repellency, low surface
energy and a resistance to soiling.
Shaped articles (e.g., fibers, films and molded or extruded
articles) of this invention can be made, e.g., by blending or
otherwise uniformly mixing the alkylated fluorochemical oligomer
and the solid synthetic polymer, for example by intimately mixing
the oligomer with pelletized or powdered polymer, and melt
extruding the mixture into shaped articles such as pellets, fibers,
or films by known methods. The oligomer can be mixed per se with
the polymer or can be mixed with the polymer in the form of a
"masterbatch" (concentrate) of the oligomer in the polymer.
Masterbatches typically contain from about 10% to about 25% by
weight of the fluorochemical additive. Also, an organic solution of
the oligomer may be mixed with the powdered or pelletized polymer,
the mixture dried to remove solvent, then melted and extruded into
the desired shaped article. Alternatively, molten oligomer (as a
compound(s) or masterbatch) can be injected into a molten polymer
stream to form a blend just prior to extrusion into the desired
shaped article.
When using thermoset resins, such as epoxy resins, urethanes and
acrylates, the alkylated fluorochemical oligomer may be mixed with
the resin and cured by application of heat. Preferably such
thermoset resins may be processed by reactive extrusion techniques
such as are taught in U.S. Pat. Nos. 4,619,976 (Kotnour) and
4,843,134 (Kotnour) the disclosures of which are herein
incorporated by reference.
The amount of oligomer in the composition is that amount sufficient
to produce a shaped article having a surface with the desired
properties of oil and water repellency and/or soiling resistance.
Preferably, the amount of oligomer will be that amount which
provides from about 100 to 10,000 ppm fluorine, more preferably 200
to 5000 ppm, most preferably 400 to 3000 ppm fluorine, based on the
weight of the shaped article.
After melt extrusion of a fiber, film or extruded article, an
annealing step may be carried out to enhance oil and water
repellency. Annealing apparently allows the fluorochemical oligomer
to migrate to the surface of the thermoplastic polymer with a
resultant increase in repellency properties, reduced surface
energy, improved solvent resistance and improved release
properties. The fiber or film is annealed at a temperature and for
a time sufficient to increase the amount of fluorochemical oligomer
at the surface. Effective time and temperature will bear an inverse
relationship to one another and a wide variety of conditions will
be suitable. Using nylon, for example, the annealing process can be
conducted below the melt temperature at about 150.degree. to
220.degree. C. for a period of about 30 seconds to 5 minutes. In
some cases, the presence of moisture during annealing, e.g., by
using an autoclave to anneal, can improve the effectiveness of the
fluorochemical oligomer. The annealing method may also serve to
reduce the amount of oligomer necessary by maximizing fluorine
content at the surface of the polymer. The oligomeric compounds of
the invention are also useful in the surface treatment of fibrous
substrates to impart improved oil and/or water repellency, and soil
and/or stain release properties.
Useful fibrous substrates which may be topically treated (surface
treated) include natural textiles and fabrics such as cotton or
wool and synthetic fabrics or textiles such as polyester or nylon,
as well as paper and leather. Topical treatment can be done via
immersion, spray, foam, kiss roll and metering. For example, the
substrate can be immersed in a dispersion or solution of the
fluorochemical oligomer and agitated until it is saturated. The
saturated substrate can then be run through a padder/roller to
remove excess dispersion, dried in an oven at a relatively low
temperature (e.g., 70.degree. C.) for a time sufficient to remove
the dispersion medium (e.g. solvents such as those used in the
oligomerization reaction), and cured at a temperature and for a
time sufficient to provide a cured treated substrate. This curing
process can be carried out at temperatures between 40.degree. C.
and about 200.degree. C. depending on the particular composition
used. In general, a temperature of about 150.degree. C. for a
period of about 10 minutes is suitable. The cured treated substrate
can be cooled to room temperature and used as desired, e.g.,
incorporated or fashioned into a garment such as rainwear.
In addition to their use in modifying the properties of fibers,
e.g., polypropylene carpet fibers, as described above, the
fluorochemical oligomers are also useful as blend additives to
thermoplastic polymer melts from which blown microfibers are made
for use in making non-woven fabrics having low surface energy, oil
and water repellency and/or soiling resistance. The resin, such as
polypropylene, used to form the melt blown microfibers should be
substantially free from materials such as antistatic agents which
could increase the electrical conductivity or otherwise interfere
with the ability of the fibers to accept and hold electrostatic
charges. When the fluorochemical compounds of the invention are
used as additives to melt blown microfibers, the additive is
preferably present in amounts of about 0.2 to 10 weight percent,
more preferably from 0.5 to 5 weight percent and most preferably
0.5 to 2 weight percent.
As used herein, the terms "fiber" and "fibrous" refer to
particulate matter, generally thermoplastic resin, wherein the
length to diameter ratio of the particulate matter is greater than
or equal to about 10. Fiber diameters may range from about 0.5
micron up to at least 1,000 microns. Each fiber may have a variety
of cross-sectional geometries, may be solid or hollow, and may be
colored by, e.g., incorporating dye or pigment into the polymer
melt prior to extrusion.
The non-woven webs of fibers of thermoplastic olefinic polymer for
use in this invention include non-woven webs manufactured by any of
the commonly known processes for producing non-woven webs. For
example, the fibrous non-woven web can be made by spunbonding
techniques or melt-blowing techniques or combinations of the two.
Spunbonded fibers are typically small diameter fibers which are
formed by extruding molten thermoplastic polymer as filaments from
a plurality of fine, usually circular capillaries of a spinneret
with the diameter of the extruded fibers being rapidly reduced.
Meltblown fibers are typically formed by extruding the molten
thermoplastic material through a plurality of fine, usually
circular, die capillaries as molten threads or filaments into a
high velocity, usually heated gas (e.g. air) stream which
attenuates the filaments of molten thermoplastic material to reduce
their diameter. Thereafter, the meltblown fibers are carried by the
high velocity gas stream and are deposited on a collecting surface
to form a web of randomly disbursed meltblown fibers. Any of the
non-woven webs may be made from a single type of fiber or two or
more fibers which differ in the type of thermoplastic olefinic
polymer and/or thickness. Alternatively, sheath-core fibers can be
extruded, containing different polymer compositions in each layer
or containing the same polymer composition in each layer but
employing the more expensive fluorochemical component in the outer
sheath layer.
The melt blown polypropylene microfibers useful in the present
invention can be prepared as described in Van Wente, A., "Superfine
Thermoplastic Fibers," Industrial Engineering Chemistry, vol. 48,
pp. 1342-1346 (1956) and in Report No. 4364 of the Naval Research
Laboratories, published May 25, 1954, entitled "Manufacture of
Super Fine Organic Fibers" by Van Wente et al. or from microfiber
webs containing particulate matter such as those disclosed, for
example, in U.S. Pat. Nos. 3,971,373 (Braun), 4,100,324 (Anderson)
and 4,429,001 (Kolpin et al.), which patents are incorporated
herein by reference. Multilayer constructions of nonwoven fabrics
enjoy wide industrial and commercial utility and include uses such
as fabrics for medical gowns and drapes. The nature of the
constituent layers of such multilayer constructions can be varied
according to the desired end use characteristics, and can comprise
two or more layers of melt-blown and spun-bond webs in may useful
combinations such as described in U.S. Pat. Nos. 5,145,727 and
5,149,576, both descriptions of which are incorporated herein by
reference. The filtering efficiency of a melt-blown microfiber web
can be improved by a factor of two or more when the melt-blown
fibers are bombarded as they issue from the orifices with
electrically charged particles such as electrons or ions, thus
making the fibrous web an electret. Similarly, the web can be made
an electret by exposure to a corona after it is collected.
Melt-blown polypropylene microfibers are especially useful, while
other polymers may also be used such as polycarbonates and
polyhalocarbons that may be melt-blown and have appropriate
volume-resistivities under expected environmental conditions.
Any of a wide variety of constructions, especially multilayer
constructions such as SMS (spunbond/meltblown/spunbond)
constructions, may be made from the above-described fibers and
fabrics, and such constructions will find utility in any
application where some level of hydrophobicity, oleophobicity (or
other fluid repellency, such as to bodily fluids) is required. The
fibers prepared from the synthetic organic polymer composition of
the invention may be used in woven and nonwoven medical fabrics
(such as drapes, gowns and masks), industrial apparel, outdoor
fabrics (such as umbrellas, awnings, tents, etc), raincoats and
other outdoor apparel, as well as home furnishings such as table
linens and shower curtains, and in myriad other related uses.
Preferably, the filter media are annealed, i.e. heated for a
sufficient time at a sufficient temperature to cause the
fluorochemical additive to bloom to the surface of the fibers.
Generally, about 1 to 10 minutes at about 140 deg. C. is sufficient
although shorter times may be used at higher temperatures and
longer times may be required at lower temperatures.
Blown microfibers for fibrous electret filters of the invention
typically have an effective fiber diameter of from about 2 to 30
micrometers, preferably from about 7 to 10 micrometers, as
calculated according to the method set forth in Davies, C. N., "The
Separation of Airborne Dust and Particles," Institution of
Mechanical Engineers, London, Proceedings 1B, 1952.
The electret filter medium of the present invention preferably has
a basis weight in the range of about 10 to 500 g/m.sup.2, more
preferably about 10 to 100 g/m.sup.2. In making melt-blown
microfiber webs, the basis weight can be controlled, for example,
by changing either the collector speed or the die throughput. The
thickness of the filter media is preferably about 0.25 to 20 mm,
more preferably about 0.5 to 2 mm. The electret filter media and
the polypropylene resin from which it is produced should not be
subjected to any unnecessary treatment which might increase its
electrical conductivity, e.g., exposure to gamma rays, ultraviolet
irradiation, pyrolysis, oxidation, etc.
The melt-blown microfibers or fibrillated fibers of the electret
filters of the invention can be electrostatically charged by a
process described in U.S. Pat. Nos. Re. 30,782 (van Turnhout) or
Re. 31,285 (van Turnhout) or by other conventional methods for
charging or polarizing electrets, e.g., by a process of U.S. Pat.
Nos. 4,375,718 (Wadsworth et al.); 4,588,537 (Klasse et al.); or
4,592,815 (Nakao). In general, the charging process involves
subjecting the material to corona discharge or pulsed high voltage.
Alternatively the fibers may be charged by impinging a jet or
stream of water droplets, followed by drying to provide the web
with filtration enhancing electret charge as described in U.S. Pat.
No. 5,496,507 (Angadjirand et al.)
This invention is illustrated by, but is not intended to be limited
to, the following examples.
EXAMPLES
Unless otherwise specified, all percentages shown in the examples
and test methods which follow are percentages by weight.
Glossary
TELOMER-A--FLUOWET.TM. AC-812 fluoroacrylate monomer,
(CH.sub.2.dbd.CHC(O)OCH.sub.2 CH.sub.2 (CF.sub.2).sub.n CF.sub.3,
where n is a value ranging from about 3 to 11 and averaging about
7, available from Hoechst Aktiengesellschaft, Frankfurt Am Main,
Germany).
MeFOSEA--C.sub.8 F.sub.17 SO.sub.2 N(CH.sub.3)C.sub.2 H.sub.4
OC(O)CH.dbd.CH.sub.2, can be prepared using the general procedure
described in U.S. Pat, No. 2,803,615.
EtFOSEA--C.sub.8 F.sub.17 SO.sub.2 N(C.sub.2 H.sub.5)C.sub.2
H.sub.4 OC(O)CH.dbd.CH.sub.2, is available as FLUORAD.TM. FX-13
fluorochemical acrylate from 3M Company, St. Paul, Minn.
MeFBSEMA--C.sub.4 F.sub.9 SO.sub.2 N(CH.sub.3)C.sub.2 H.sub.4
OC(O)C(CH.sub.3).dbd.CH.sub.2, can be prepared using the general
procedure described in U.S. Pat, No. 2,803,615.
MeFBSEA--C.sub.4 F.sub.9 SO.sub.2 N(CH.sub.3)CH.sub.2 CH.sub.2
OC(O)CH.dbd.CH.sub.2, can be prepared using the general procedure
described in U.S. Pat. No. 2,803,615.
MeFOSEMA--C.sub.8 F.sub.17 SO.sub.2 N(CH.sub.3)C.sub.2 H.sub.4
OC(O)C(CH.sub.3).dbd.CH.sub.2, can be prepared by the general
procedure described in U.S. Pat. No. 2,803,615.
UNILIN.TM. 700--polyethylene 700 alcohol (having around 50 carbon
atoms), available from Baker Petrolite Corp., Tulsa, Okla.
UNILIN.TM. 425--polyethylene 460 alcohol (having around 32 carbon
atoms), available from Baker Petrolite Corp.
PRIPOL.TM. 1070--dimer diol made from oleyl alcohol, available from
Henkel Corp., Cincinnati, Ohio.
MeFOSE--C.sub.8 F.sub.17 SO.sub.2 N(CH.sub.3)CH.sub.2 CH.sub.2 OH,
can be prepared using the general procedure described in Example 3
of U.S. Pat. No. 2,803,656.
UNICID.TM. 700--polyethylene 700 acid (having around 50 carbon
atoms), available from Petrolite Corp., St. Louis, Mo.
UNITHOX.TM.750--CH.sub.3 CH.sub.2 (CH.sub.2 CH.sub.2).sub.x
CH.sub.2 CH.sub.2 (OCH.sub.2 CH.sub.2).sub.y OH, where x is around
23 and y is around 17, available from Baker Petrolite Corp.
EMPOL.TM. 1008--distilled and hydrogenated dimer acid made from
oleic acid, having an acid equivalent weight of 305 as determined
by titration, available from Henkel Corp./Emery Group, Cincinnati,
Ohio.
3-mercaptopropionic acid--HSCH.sub.2 CH.sub.2 COOH, available from
Aldrich Chemical Co., Milwaukee, Wis.
methyl 3-mercaptopropionate--HSCH.sub.2 CH.sub.2 COOCH.sub.3,
available from Aldrich Chemical Co.
2-mercaptoethanol--HSCH.sub.2 CH.sub.2 OH, available from Aldrich
Chemical Co.
3-mercapto-1,2-propanediol - HSCH.sub.2 CH(OH)CH.sub.2 OH,
available from Aldrich Chemical Co.
AIBN--2,2'-azobisisobutyronitrile, available as VAZO.TM. 64
initiator from E. I. duPont de Nemours & Co., Wilmington,
Del.
FC Oxazolidinone A--a polymer melt additive prepared by reacting
C.sub.8 F.sub.17 SO.sub.2 N(CH.sub.3)CH(OH)CH.sub.2 Cl with stearyl
isocyanate at a 1:1 molar ratio followed by ring closure using
essentially the same procedure as described in Scheme I of U.S.
Pat. No. 5,025,052 (Crater et al.).
FC Oxazolidinone B--a polymer melt additive prepared by reacting
C.sub.8 F.sub.17 SO.sub.2 N(Me)CH(OH)CH.sub.2 Cl with hexamethylene
diisocyanate at a 2:1 molar ratio followed by ring closure using
essentially the same procedure as described in Scheme I of U.S.
Pat. No. 5,025,052 (Crater et al.).
PP3505--Escorene.TM. PP3505 polypropylene, having a 400 melt index
flow rate, available from Exxon Chemical Co., Baytown, Tex.
PP3445--Escorene.TM. PP3445 polypropylene, having a 35 melt index
flow rate, available from Exxon Chemical Co.
PE6806--Aspun.TM. 6806 polyethylene, having a melt flow index of
105 g/10 min (as measured by Test Method ASTM D-1238) and having a
peak melting point of 124.8.degree. C., available from Dow Chemical
Co., Midland, Mich.
PS440-200--Morthane.TM. PS440-200 urethane, available from Morton
Thiokol Corp., Chicago, Ill.
Preparation of Compounds and Intermediates
(TELOMER-A).sub.4 --S--CH.sub.2 CH.sub.2 COOH--To a round bottom
flask equipped with stirrer, heating mantle, thermometer, reflux
condenser and nitrogen bubbler was added 375 g (0.652 mol) of
TELOMER-A and 400 g of ethyl acetate. The contents of the flask
were stirred and nitrogen was bubbled through the resulting
solution for 15 minutes. To the mixture was then added 17.3 g
(0.163 mol) of 3-mercaptopropionic acid, and nitrogen bubbling was
continued for another 2 minutes. 0.5 wt % of AIBN was then added,
and the resulting catalyzed mixture was heated to 65.degree. C. for
approximately 15 hours under a nitrogen atmosphere. IR spectra of
this material showed the absence of a>C.dbd.C<peak at 1637
cm.sup.-1, indicating no residual monomer left in the polymer. The
polymer solution was poured into hexanes, causing the polymer to
precipitate as a white powder, which was removed by filtration and
dried under vacuum.
(MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 COOH--This macromer acid was
prepared using essentially the same procedure as described for
preparing (TELOMER-A).sub.4 --S --CH.sub.2 CH.sub.2 COOH, except
that the TELOMER-A was replaced with an equimolar amount of
MeFOSEA.
(EtFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 COOH--This macromer acid was
prepared using essentially the same procedure as described for
preparing (TELOMER-A).sub.4 --S --CH.sub.2 CH.sub.2 COOH, except
that the TELOMER-A was replaced an equimolar amount of EtFOSEA.
(MeFBSEMA).sub.4 --S--CH.sub.2 CH.sub.2 OH--To a round bottom flask
equipped with stirrer, thermometer, reflux condenser and nitrogen
bubbler was added 501 g (1.179 mol) of MeFBSEMA and 500 mL of ethyl
acetate. The contents of the flask were stirred to form a solution,
and nitrogen was bubbled through the solution for 15 minutes. To
this solution was then added 23.03 g (0.295 mol) of
2-mercaptoethanol, and nitrogen was bubbled through the contents of
the flask for an additional 2 minutes. 0.5% by weight of AIBN was
added and the resulting mixture heated to 65.degree. C. for
approximately 15 hours under a nitrogen atmosphere. IR spectra of
this material showed the absence of a >C.dbd.C<peak at 1637
cm.sup.-1, indicating no residual monomer present. The polymer
solution was poured in hexanes, causing the polymer to precipitate
as a viscous liquid, which was removed by decantation and dried
under vacuum.
(MeFBSEA).sub.4 --S--CH.sub.2 CH.sub.2 OH--This macromer alcohol
was prepared using essentially the same procedure as described for
preparing (MeFBSEMA).sub.4 --S--CH.sub.2 CH.sub.2 OH, except that
MeFBSEMA was replaced with an equi molar amount of MeFBSEA.
(MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 OH--This macromer alcohol
was prepared using essentially the same procedure as described for
preparing (MeFBSEMA).sub.4 --S--CH.sub.2 CH.sub.2 OH, except that
MeFBSEMA was replaced with an equimolar amount of MeFOSEA. .sup.1 H
and .sup.13 C NMR analysis showed the degree of polymerization to
be slightly greater than 4.
(MeFOSEA).sub.9 --S--CH.sub.2 CH.sub.2 OH--This macromer alcohol
was prepared using the same procedure as described for preparing
(MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 OH, except that the batch
size was scaled up and it is believed that the amount of
2-mercaptoethanol was decreased. In this case, .sup.1 H and .sup.13
C NMR analysis showed the degree of polymerization to be 9.
(MeFOSEMA).sub.4 --S--CH.sub.2 CH.sub.2 OH--This macromer alcohol
was prepared using essentially the same procedure as described for
preparing (MeFBSEMA).sub.4 --S--CH.sub.2 CH.sub.2 OH, except that
MeFBSEMA was replaced with an equimolar amount of MeFOSEMA.
(MeFOSEA).sub.4 --S--CH.sub.2 CH(OH)CH.sub.2 OH--To a round bottom
flask equipped with stirrer, thermometer, reflux condenser and
nitrogen bubbler was added 400 g (0.655 mol) of MeFOSEA and 400 mL
of ethyl acetate. While stirring, nitrogen was bubbled through the
resulting solution for 15 minutes. To this solution was added 17.7
g (0.164 mol) of 3-mercapto-1,2-propanediol, and bubbling with
nitrogen was continued for another 2 minutes. 0.5% (wt) of AIBN was
added and the mixture was heated to 65.degree. C. for about 15
hours under a nitrogen atmosphere. IR spectra of this material
showed the absence of >C.dbd.C<peak at 1637 cm.sup.-1,
indicating no residual monomer. This mixture was poured in CH.sub.3
OH and the resulting white powder was filtered and dried under
vacuum.
(MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 COOCH.sub.3 --To a round
bottom equipped with stirrer, thermometer, reflux condenser and
nitrogen bubbler was added 200 g (0.327 mol) of MeFOSEA and 200 g
of ethyl acetate. The resulting mixture was stirred for 15 minutes,
during which time the mixture was bubbled with nitrogen. To the
mixture was then added 9.8 g (0.817 mol) of methyl
3-mercaptopropionate, and nitrogen was bubbled through the mixture
for an additional two minutes. 0.5% by weight of AIBN initiator was
added, and the resulting mixture was heated to 65.degree. C. for
about 15 hours under a nitrogen atmosphere. IR spectra analysis of
the resulting polymer solution showed an absence of the
>C.dbd.C<peak at 1637 cm.sup.-1, indicating essentially no
residual monomer. The polymer solution was poured into methanol,
causing formation of a white precipitation of the polymer which was
removed by filtration and dried under vacuum.
(MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 COO-UNILIN.TM. 700--To a
3-necked round bottom flask equipped with a mechanical stirrer and
Dean-Stark apparatus was added 50 g (0.0197 mol) of (MeFOSEA).sub.4
--S--CH.sub.2 CH.sub.2 COOH, 13.8 g (0.0197 mol) of UNILIN.TM. 700,
0.5 mL of methanesulfonic acid and 100 mL of toluene. The resulting
mixture was heated to reflux for approximately 15 hours, during
which time 0.3 mL of water had collected in the Dean-Stark
apparatus. IR spectra of this mixture showed no --COOH or --OH
peaks. To this hot mixture 10 g of Ca(OH).sub.2 was added slowly
with stirring, and the hot solution was filtered. Toluene was
removed from the filtrate by heating under reduced pressure, and
the remaining solids were dried in a vacuum oven. Differential
scanning calorimetry (DSC) analysis of this sample showed a melting
transition at 101.4.degree. C., and thermogravimetric analysis
(TGA) showed onset of degradation at 330.degree. C. in air.
(EtFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 COO-UNILIN.TM. 700--This
ester was prepared using essentially the same procedure as
described for preparing (MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2
COO--UNILIN.TM. 700, except that the (MeFOSEA).sub.4 --S--CH.sub.2
CH.sub.2 COOH was replaced with an equimolar amount of
(EtFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 COOH.
(TELOMER-A).sub.4 --S--CH.sub.2 CH.sub.2 COO-UNILIN.TM. 700--This
ester was prepared using essentially the same procedure as
described for preparing (MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2
COO-UNILIN.TM. 700, except that the (MeFOSEA).sub.4 --S--CH.sub.2
CH.sub.2 COOH was replaced with an equimolar amount of
(TELOMER-A).sub.4 --S--CH.sub.2 CH.sub.2 COOH.
(MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 COO-UNILIN.TM. 425--This
ester was prepared using essentially the same procedure as
described for preparing (MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2
COO--UNILIN.TM. 700, except that the UNILIN.TM. 700 was replaced
with an equimolar amount of UNILIN.TM. 425.
(EtFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 COO-UNILIN.TM. 425--This
ester was prepared using essentially the same procedure as
described for preparing (MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2
COO--UNILIN.TM. 425, except that the (MeFOSEA).sub.4 --S--CH.sub.2
CH.sub.2 COOH was replaced with an equimolar amount of
(EtFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 COOH.
(TELOMER-A).sub.4 --S--CH.sub.2 CH.sub.2 COO-UNILIN.TM. 425--This
ester was prepared using essentially the same procedure as
described for preparing (MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2
COO-UNILIN.TM. 425, except that the (MeFOSEA).sub.4 --S--CH.sub.2
CH.sub.2 COOH was replaced with an equimolar amount of
(TELOMER-A).sub.4 --S--CH.sub.2 CH.sub.2 COOH.
(MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 COOC.sub.8 H.sub.37 --This
ester was prepared using essentially the same procedure as
described for preparing (MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2
COO--UNILIN.TM. 700, except that the UNILIN.TM. 700 was replaced
with an equimolar amount of stearyl alcohol.
(MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 COOC.sub.22 H.sub.45 --This
ester was prepared using essentially the same procedure as
described for preparing (MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2
COO-UNILIN.TM. 700, except that the UNILIN.TM. 700 was replaced
with an equimolar amount of behenyl alcohol.
[(MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 COO].sub.2 -PRIPOL.TM. 1070
--To a 3-necked round bottom flask equipped with a mechanical
stirrer and Dean-Stark apparatus was added 50 g (0.0197 mol) of
(MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 COOH, 5.7 g (0.0098 mol) of
PRIPOL.TM. 1070, 0.5 mL of methanesulfonic acid and 100 mL of
toluene. The resulting mixture was heated to reflux for
approximately 15 hours, during which time 0.3 mL of water had
collected in the Dean-Stark apparatus. IR spectra of this mixture
showed no --COOH or --OH peaks. To this hot mixture 10 g of
Ca(OH).sub.2 was added slowly with stirring, and the hot solution
was filtered. Toluene was removed from the filtrate by heating
under reduced pressure, and the remaining solids were dried in a
vacuum oven.
(MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 COOCH.sub.2 CH.sub.2
N(CH.sub.3)SO.sub.2 C.sub.8 F.sub.17 --To a 3-necked round bottom
flask equipped with a mechanical stirrer and Dean-Stark apparatus
was added 50 g (0.0197 mol) of(MeFOSEA).sub.4 --S--CH.sub.2
CH.sub.2 COOH, 10.6 g (0.019 mol) of MeFOSE, 0.5 mL of
methanesulfonic acid and 100 mL of toluene. The resulting mixture
was heated to reflux for approximately 15 hours, during which time
0.3 mL of water had collected in the Dean-Stark apparatus. IR
spectra of this mixture showed no --COOH or --OH peaks. To this hot
mixture 10 g of Ca(OH).sub.2 was slowly added with stirring, and
the hot solution was filtered. Toluene was removed from the
filtrate by heating under reduced pressure, and the remaining
solids were dried in a vacuum oven.
(MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 COO-UNITHOX.TM. 750--This
ester was prepared using essentially the same procedure as
described for preparing (MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2
COO-UNILIN.TM. 700, except that the UNILIN.TM. 700was replaced with
an equimolar amount of UNITHOX.TM. 750.
(MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 OOC-UNICID.TM. 700--To a
3-necked round bottom flask equipped with a mechanical stirrer and
Dean-Stark apparatus was added 100 g (0.039 mol) of (MeFOSEA).sub.4
--S--CH.sub.2 CH.sub.2 OH, 34.5 g (0.039 mol) of UNICID.TM. 700,
1.0 mL of methanesulfonic acid and 100 mL of toluene. The resulting
mixture was heated to reflux for approximately 15 hours, during
which time some water had collected in the Dean-Stark apparatus. IR
spectra of this mixture showed no --COOH or --OH peaks. To this hot
mixture 10 g of Ca(OH).sub.2 was added slowly with stirring, and
the hot solution was filtered. Toluene was removed from the
filtrate by heating under reduced pressure, and the remaining
solids were dried in a vacuum oven. .sup.1 H and .sup.13 C NMR
analysis showed the degree of polymerization to be 4.2, as
calculated from the ratio of the methyl moiety located on the
sulfonamido nitrogen to the terminal methyl moiety of the long
chain alkyl group.
(MeFOSEA).sub.9 --S--CH.sub.2 CH.sub.2 OOC-UNICID.TM. 700--This
ester was prepared using essentially the same procedure as
described for preparing (MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2
COO--UNICID.TM. 700, except that the (MeFOSEA).sub.4 --S--CH.sub.2
CH.sub.2 OH was replaced with an equimolar amount of
(MeFOSEA).sub.9 --S--CH.sub.2 CH.sub.2 OH.
(MeFOSEMA).sub.4 --S--CH.sub.2 CH.sub.2 OOC-UNICID.TM. 700--This
ester was prepared using essentially the same procedure as
described for preparing (MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2
COO-UNICID.TM. 700, except that the (MeFOSEA).sub.4 --S--CH.sub.2
CH.sub.2 OH was replaced with an equimolar amount of
(MeFOSEMA).sub.4 --S--CH.sub.2 CH.sub.2 OH.
(MeFBSEA).sub.4 --S--CH.sub.2 CH.sub.2 OOC-UNICID.TM. 700--This
ester was prepared using essentially the same procedure as
described for preparing (MeFOSEA).sub.4 --S--CH.sub.2
COO--UNILIN.TM. 700, except that the (MeFOSEA).sub.4 --S--CH.sub.2
CH.sub.2 CO.sub.2 H was replaced with an equimolar amount of
(MeFBSEA).sub.4 --S--CH.sub.2 CH.sub.2 OH and UNILIN.TM. 700 was
replaced with an equimolar amount of UNICID.TM. 700.
(MeFBSEMA).sub.4 --S--CH.sub.2 CH.sub.2 OOC-UNICID.TM. 700--This
ester was prepared using essentially the same procedure as
described for preparing (MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2
COO--UNILIN.TM. 700, except that the (MeFOSEA).sub.4 --S--CH.sub.2
CH.sub.2 CO.sub.2 H was replaced with an equimolar amount of
(MeFBSEMA).sub.4 --S--CH.sub.2 CH.sub.2 H and UNILIN.TM. 700 was
replaced with an equimolar amount of UNICID.TM. 700.
(MeFOSEA).sub.4 --S--CH.sub.2 CH(OOCC.sub.17 H.sub.35)CH.sub.2
OOCC.sub.17 H.sub.35 --To a 3-necked round bottom flask equipped
with a mechanical stirrer and Dean-Stark apparatus was added 50 g
(0.0196 mol) of (MeFOSEA).sub.4 --S--CH.sub.2 CH(OH)CH.sub.2 OH,
11.2 g (0.0392 mol) of stearic acid, 0.5 mL of methanesulfonic acid
and 100 mL of toluene. The resulting mixture was heated to reflux
for approximately 15 hours, during which time some water had
collected in the Dean-Stark apparatus. IR spectra of this mixture
showed no --COOH or --OH peaks. To this hot mixture 10 g of
Ca(OH).sub.2 was added slowly with stirring, and the hot solution
was filtered. Toluene was removed from the filtrate by heating
under reduced pressure, and the remaining solids were dried in a
vacuum oven.
C.sub.8 F.sub.17 SO.sub.2 N(CH.sub.3)CH.sub.2 CH.sub.2
OOC-UNICID.TM. 700--To a 3-necked round bottom flask equipped with
a mechanical stirrer and Dean-Stark apparatus was added 135 g
(0.242 mol) of MeFOSE, 215.7 g (0.242 mol) of UNICID.TM. 700, 3.5 g
of methanesulfonic acid and 400 mL of toluene. The resulting
mixture was heated to reflux for approximately 15 hours, during
which time water had collected in the Dean-Stark apparatus. IR
spectra of this mixture showed no --COOH or --OH peaks. To this hot
mixture 10 g of Ca(OH).sub.2 was added slowly with stirring, and
the hot solution was filtered. Toluene was removed from the
filtrate by heating under reduced pressure, and the remaining
solids were dried in a vacuum oven.
[C.sub.8 F.sub.17 SO.sub.2 N(CH.sub.3)CH.sub.2 CH.sub.2 OOC].sub.2
-EMPOL.TM. 1008--To a 500 mL 2-necked round-bottom flask equipped
with overhead condenser, thermometer and Dean-Stark trap wrapped
with heat tape was charged 57.8 g (0.190 eq) of Empol.TM. 1008
dimer acid, 100 g (0.185 eq) of MeFOSE, 1 g of p-toluenesulfonic
acid and 50 g of toluene. The resulting mixture was placed in an
oil bath heated to 150.degree. C. The degree of esterification was
monitored by measuring the amount of water collected in the
Dean-Stark trap and also by using gas chromatography to determine
the amount of unreacted fluorochemical alcohol. After 18 hours of
reaction, about 2.8 mL of water was collected and a negligible
amount of fluorochemical alcohol remained, indicating a complete
reaction. The reaction mixture was then cooled to 100.degree. C.
and was twice washed with 120 g aliquots of deionized water to a
water pH of 3. The final wash was removed from the flask by
suction, and the reaction mixture was heated to 120.degree. C. at
an absolute pressure of about 90 torr to remove volatiles. The
product, a brownish solid, was characterized as containing the
desired product by .sup.1 H and .sup.13 C NMR spectroscopy and
thermogravimetric analysis.
[(MeFBSEA).sub.4 --S--CH.sub.2 CH.sub.2 OOC].sub.2 -EMPOL.TM.
1008--This ester was prepared using essentially the same procedure
as described for preparing C.sub.8 F.sub.17 SO.sub.2
N(CH.sub.3)CH.sub.2 CH.sub.2 OOC].sub.2 -EMPOL.TM. 1008, except
that the C.sub.8 F.sub.17 SO.sub.2 N(CH.sub.3)CH.sub.2 CH.sub.2 OH
was replaced with an equimolar amount of (MeFBSEA).sub.4
--S--CH.sub.2 CH.sub.2 OH.
[(MeFBSEMA).sub.4 --S--CH.sub.2 CH.sub.2 OOC].sub.2 -EMPOL.TM. 1008
--This ester was prepared using essentially the same procedure as
described for preparing C.sub.8 F.sub.17 SO.sub.2
N(CH.sub.3)CH.sub.2 CH.sub.2 OOC].sub.2 -EMPOL.TM. 1008, except
that the C.sub.8 F.sub.17 SO.sub.2 N(CH.sub.3)CH.sub.2 CH.sub.2 OH
was replaced with an equimolar amount of (MeFBSEMA).sub.4
--S--CH.sub.2 CH.sub.2 OH.
Test Methods
Melt-Blown Extrusion Procedure--The melt-blown extrusion procedure
used is the same as described in U.S. Pat. No. 5,300,357, column
10, which is herein incorporated by reference. The extruder used is
a Brabender 42 mm conical twin screw extruder, with maximum
extrusion temperature of 270-280.degree. C. and distance to the
collector of 12 inches (30 cm).
Fluorochemical and thermoplastic polymer mixtures are mixed by
blending the thermoplastic polymer and fluorochemical polymer melt
additive (if used) in a paperboard container using a mixer head
affixed to a hand drill for about one minute until a visually
homogeneous mixture is obtained.
The process condition for each mixture is the same, including the
melt blowing die construction used to blow the microfiber web, the
basis weight of the web (55.+-.5 g/m.sup.2) and the diameter of the
microfibers (5-18 micrometers). Unless otherwise stated, the
extrusion temperature is 270-280.degree. C., the primary air
temperature is 210.degree. C., the pressure is 124 kPa (18 psi),
with a 0.076 cm air gap width, and the polymer throughput rate is
about 180 g/hr/cm.
Film Extrusion Procedure--Films were extruded from Escorene.TM.
PP3445 polypropylene containing either 3% by weight of
fluorochemical polymer melt additive or no polymer melt additive
using the following procedure. A 25 mm twin screw Bersdorf extruder
equipped with a gear pump and slot die having a slot approximately
12 inches (30 cm) wide was fed with Colortronic.TM. Model CSD
(Freidrichsdorf, Germany) dosing units providing 97 wt %
polypropylene and 3 wt % of the additive. The extruder was heated
so that the extruder and die temperatures were 380.degree. F.
(197.degree. C.) and the melt temperature was 401.degree. F.
(205.degree. C.). The molten polymer composition was extruded at a
rate of about 9 kg/hr onto a casting roll (at 61.degree. C.)to give
a film having a thickness of about 7 mil (0.3 mm). The film was
allowed to cool before testing.
Water Repellency Test--Nonwoven web samples were evaluated for
water repellency using 3M Water Repellency Test V for
Floorcoverings (February 1994), available from 3M Company. In this
test, samples are challenged to penetrations by blends of deionized
water and isopropyl alcohol (IPA). Each blend is assigned a rating
number as shown below:
Water Repellency Rating Number Blend (% by volume) 0 100% water 1
90/10 water/IPA 2 80/20 water/IPA 3 70/30 water/IPA 4 60/40
water/IPA 5 50/50 water/IPA 6 40/60 water/IPA 7 30/70 water/IPA 8
20/80 water/IPA 9 10/90 water/IPA 10 100% IPA
In running the Water Repellency Test, a nonwoven web sample is
placed on a flat, horizontal surface. Five small drops of water or
a water/IPA mixture are gently placed at points at least two inches
apart on the sample. If, after observing for ten seconds at a
45.degree. angle, four of the five drops are visible as a sphere or
a hemisphere, the nonwoven web sample is deemed to pass the test.
The reported water repellency rating corresponds to the highest
numbered water or water/IPA mixture for which the nonwoven sample
passes the described test.
It is desirable to have a water repellency rating of at least 4,
preferably a rating at least 6.
Oil Repellency Test--Nonwoven web samples were evaluated for oil
repellency using 3M Oil Repellency Test III (February 1994),
available from 3M Company, St. Paul, Minn. In this test, samples
are challenged to penetration by oil or oil mixtures of varying
surface tensions. Oils and oil mixtures are given a rating
corresponding to the following:
Oil Repellency Oil Rating Number Composition 0 (fails Kaydol .TM.
mineral oil) 1 Kaydol .TM. mineral oil 2 65/35 (vol) mineral
oil/n-hexadecane 3 n-hexadecane 4 n-tetradecane 5 n-dodecane 6
n-decane 7 n-octane 8 n-heptane
The Oil Repellency Test is run in the same manner as is the Water
Repellency Test, with the reported oil repellency rating
corresponding to the highest oil or oil mixture for which the
nonwoven web sample passes the test.
It is desirable to have an oil repellency rating of at least 1,
preferably a rating of at least 3.
DOP Wetting Time Test--Nonwoven webs were challenged to wetting by
dioctyl phthalate (DOP) by placing a small drop of neat DOP on the
web and measuring the time for the drop to spread or wet the web
(considered the time of failure). Webs which were not wet after two
days were considered to be resistant indefinitely to DOP.
DOP Penetration and Pressure Drop Test--0.3 micrometer diameter
particles of dioctyl phthalate (DOP) at a concentration of between
70 and 110 mg/m.sup.3 are generated using a TSI No. 212 sprayer
with four orifices and 30 psi (1550 torr) clean air. The particles
are forced through the center 4.5 inch (11.4 cm) diameter portion
of a circular sample of filter media which is 5.25 inches (13.3 cm)
in diameter at a rate of 42.5 L/min, which represents a face
velocity of 6.9 centimeters per second. The sample is exposed to
the aerosol for 30 to 60 seconds until the readings stabilize. The
DOP penetration (% Pn) is measured with an optical scattering
chamber (Percent Penetration Meter Model TPA-8F, available from Air
Techniques. Inc.). The DOP penetration is preferably less than
about 40%, more preferably less than about 30%. The pressure drop
is measured at a flow rate of 42.5 L/min and a face velocity of 6.9
cm/sec using an electronic manometer.
Pressure drop, .DELTA.P, is reported in units of millimeters of
water. Preferably the pressure drop is less than about 4, more
preferably less than about 3.
The penetration and pressure drop are used to calculate a quality
value (QF, having units of mm H.sub.2 O.sup.-1) defined by the
following formula:
A higher initial QF value indicates better initial filtration
performance. Decreased QF values effectively correlate with
decreased filtration performance. Generally a QF value of at least
about 0.25 is preferred, a value of at least about 0.4 is more
preferred and a value of at least about 0.5 is most preferred.
DOP Loading Test--The same procedure was used as described in the
DOP Penetration and Pressure Drop Test with the following
modifications. A nonwoven web sample is weighed and then placed in
a sample holder which exposed the center 4.5 inch (11.4 cm)
diameter portion of the circular sample. A computer is interfaced
to record measurements of DOP penetration and pressure drop every
minute over a 45 minute period. After this period, the nonwoven
sample with collected DOP aerosol is removed, the sample is
reweighed, and the penetration is plotted as a function of the DOP
weight collected on the web.
Contact Angle Test Procedure--The following procedure was used to
measure both advancing and receding contact angles.
A sample of clean polyester film is cut into 85 mm.times.13 mm
rectangular strips. Each strip is cleaned by dipping the strip in
and out of methyl alcohol, wiping the strip with a Kimwipe.TM.
wiper (commercially available from Kimberly-Clark Corp., Boswell,
Ga.), taking care not to hand-touch the strip's surface, and
allowing the strip to dry for 15 minutes. Then, using a small
binder clip to hold one end of the strip, the strip is immersed in
a treating solution consisting of a 3% (wt) solution of the
alkylated fluorochemical oligomer compound in either
.alpha.,.alpha.,.alpha.-trifluorotoluene or 50/50 (wt)
.alpha.,.alpha., .alpha.-trifluorotoluene/toluene, and the strip is
then withdrawn slowly and smoothly from the solution. The coated
film strip is tilted to allow any solution runoff to accumulate at
the corner of the strip, and a Kimwipe.TM. tissue is touched to the
corner to pull away the solution buildup. The coated film strip is
allowed to air dry in a protected location for a minimum of 30
minutes and then is baked for 10 minutes at 150.degree. C. to dry
and cure the coating.
After the treatment is dry and cured, a drop of n-hexadecane is
applied to the treated film strip and the advancing or receding
contact angle of the drop is measured using a CAHN Dynamic Contact
Angle Analyzer, Model DCA 322 (a Wilhelmy balance apparatus
equipped with a computer for control and data processing, available
from ATI, Madison, Wis.) using the following procedure. The CAHN
Dynamic Contact Angle Analyzer is calibrated using a 500 mg weight.
An alligator clip is fastened to a piece of coated film strip about
30 mm long, and the clip and film piece are hung from the stirrup
of the balance. A 30 mL glass beaker containing approximately 25 mL
of n-hexadecane is placed under the balance stirrup, and the beaker
is positioned so that the coated film strip is centered over the
beaker and its contents but not touching the walls of the beaker.
Using the lever on the left side of the apparatus, the platform
supporting the beaker is carefully raised until the surface of
n-hexadecane is 2-3 mm from the lower edge of the film strip. The
door to the apparatus is closed, the "Configure" option is chosen
from the "Initialize" menu of the computer, the "Automatic" option
is chosen from the "Experiment" menu, and the computer program then
calculates the time for a total of 3 scans. The result should be a
time interval of 1 second and estimated total time of 5 minutes,
which are the acceptable settings to show the baseline weight of
the sample. The Return Key is then pressed to begin the automatic
measurement cycle. 10 readings of the baseline are taken before the
scan begins. The apparatus then raises and lowers the liquid so
that 3 scans are taken. The "Least Squares" option is then selected
from the "Analysis" menu, and the average advancing or receding
contact angle is calculated from the 3 scans of the film sample.
The 95% confidence interval for the average of the 3 scans is
typically about.+-.1.2.degree..
Peel Force Test Procedure--Release of pressure-sensitive adhesive
tape was measured using a "peel force" test procedure. In this
test, a 1.9 cm (0.75 in) wide by 20 cm (8 in) long strip of 3M #850
acrylic adhesive tape was dry-laminated by hand to the melt blended
film and was secured with two passes of a 2 kg rubber roller. The
peel force to remove the tape from the paper at an angle of
180.degree. and at a peel rate of 229 cm/min (90 in/min) was then
measured using an IMASS SP-102B-3M90 peel tester (available from
Instrumentors Inc.). Peel force was measured on one sample
immediately after preparation ("Initial") and on another sample
after aging for two days at 49.degree. C. (120.degree. F.) and
ambient humidity using a forced air oven followed by cooling for
1/2 hour at 50% humidity ("Aged").
Examples 1-19 and Comparative Examples C1-C5
In Examples 1-19, several alkylated fluorochemical oligomeric
compounds having an ester moiety-containing linking group were each
evaluated at 1% or 2% in PP3505 polypropylene as repellent polymer
melt additives. Melt-blown nonwoven webs were made according to the
Melt-Blown Extrusion Procedure, and the resulting webs were
evaluated for repellency using the Water Repellency Test and the
Oil Repellency Test, both initially and after running the Embossing
Procedure. Also, the resistance time of the nonwoven webs to
dioctyl phthalate was measured using the DOP Wetting Time Test.
Measurements were made initially and again after heating at
120.degree. C. for 10 minutes. In Comparative Examples C1-C2, two
fluorochemical compounds having an aliphatic moiety, an ester
moiety-containing linking group but non-oligomeric (i.e., single
chain) fluorochemical portion(s) were evaluated in the same fashion
as an additive to PP3505 prior to extruding the nonwoven web. Both
of these fluorochemicals are known in the art to be repellent
ester-containing polymer melt additives and are described in World
Published Patent Applications WO 97/22659 and WO 99/05345,
respectively.
In Comparative Examples C3-C4, two non-oligomeric fluorochemicals
known to be effective polymer melt additives were evaluated in the
same fashion as an additive to PP3505 prior to extruding the
nonwoven web. FX-1801 (Comp. Ex. C3) is used commercially as a
polymer melt additive.
In Comparative Example C5, no polymer melt additive was
incorporated into the polypropylene prior to extruding the nonwoven
web.
Results are presented in TABLE 1.
TABLE 1 Water Rep.: Oil Rep.: Fluorochemical Additive: Anne Annea
DOP Wet. Ex. Name % Init. aled. Init. led. Time 1 (MeFOSEA).sub.4
--S--CH.sub.2 CH.sub.2 COOC.sub.18 H.sub.37 1 3 8 0 1 immed. 2
(MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 COOC.sub.22 H.sub.43 1 3 9 0
1 immed. 3 (MeFOSEA).sub.4 --S--CH.sub.2 -- 1 3 9 0 7 3 days
CH(OOCC.sub.17 H.sub.35)CH.sub.2 OOCC.sub.17 H.sub.35 4
(MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 COO-- 1 3 8 0 2 32 min.
UNILIN .TM. 425 5 (EtFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 COO-- 1 4
9 0 2 10 sec. UNILIN .TM. 425 6 (TELOMER-A).sub.4 --S--CH.sub.2
CH.sub.2 COO-- 1 5 10 0 3 4 days UNILIN .TM. 425 7 (MeFOSEA).sub.4
--S--CH.sub.2 CH.sub.2 COO-- 1 3 9 0 5 >2 days UNILIN .TM. 700 8
(EtFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 COO-- 1 3 9 0 5 >2 days
UNILIN .TM. 700 9 (TELOMER-A).sub.4 --S--CH.sub.2 CH.sub.2 COO-- 1
3 10 0 5 >2 days UNILIN .TM. 700 10 (MeFOSEA).sub.4
--S--CH.sub.2 CH.sub.2 OOC-- 1 3 9 0 5 >2 days UNICID .TM. 700
11 (MeFOSEA).sub.9 --S--CH.sub.2 CH.sub.2 OOC 1 3 6 0 1 1 min.
UNICID .TM. 700 12 (MeFOSEMA).sub.4 --S--CH.sub.2 CH.sub.2 OOC-- 1
3 9 0 2 >2 days UNICID .TM. 700 13 (MeFBSEA).sub.4 --S--CH.sub.2
CH.sub.2 OOC-- 1 3 5 0 1 2 min. UNICID .TM. 700 14 (MeFBSEMA).sub.4
--S--CH.sub.2 CH.sub.2 OOC-- 2 3 8.5 0 5 60 min UNICID .TM. 700 15
[(MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 COO].sub.2 -- 1 3.5 8 0 0.5
immed. PRIPOL{character pullout} 1070 16 [(MeFBSEA).sub.4
--S--CH.sub.2 CH.sub.2 OOC].sub.2 -- 2 3 6 0 1 5 sec. EMPOL .TM.
1008 17 [(MeFBSEMA).sub.4 --S--CH.sub.2 CH.sub.2 OOC].sub.2 -- 2 3
6 0 5.5 10 sec. EMPOL .TM. 1008 18 (MeFOSEA).sub.4 --S--CH.sub.2
CH.sub.2 COOCH.sub.3 1 3 8 0 4 3.5 hr. 18A (MeFOSEA).sub.4
--S--CH.sub.2 CH.sub.2 COO-- 1 3 7 0 5 NOT UNITHOX .TM. 750 RUN 19
(MeFOSEA).sub.4 --S-- 1 3 7 0 3 2 min. CH.sub.2 CH.sub.2
COOCH.sub.2 CH.sub.2 N(CH.sub.3)SO.sub.2 C.sub.8 F.sub.17 C1
C.sub.8 F.sub.17 SO.sub.2 N(CH.sub.3)CH.sub.2 CH.sub.2 OOC-- 1 4.5
5 0 0 10 sec. UNICID .TM. 700 C2 [C.sub.8 F.sub.17 SO.sub.2
N(CH.sub.3)CH.sub.2 CH.sub.2 OOC].sub.2 -- 1 7 9 1 2 immed. EMPOL
.TM. 1008 C3 FC Oxazolidinone A 1 9 9 2 2 >2 days C4 FC
Oxazolidinone B 1 3 7 0 0 >2 days C5 No Additive -- 2 2 0 0
immed.
The data in TABLE 1 show that the compounds of the invention which
have fluorochemical oligomeric portions, an aliphatic moiety and a
ester moiety-containing linking group generally exhibited good to
excellent water and oil resistance after embossing. Additionally,
they exhibited good to excellent resistance to penetration by DOP.
The good repellency to oils and DOP is surprising, considering the
size of the oleophilic hydrocarbon groups attached to the compounds
(except for Ex. 18). The fluorochemical oligomeric portion
containing 9 fluoroaliphatic groups (Ex. 11) was inferior in
performance to its counterpart containing only 4 fluoroaliphatic
groups (Ex. 10), which was unexpected considering the compound of
Ex. 10 contains much less organofluorine. The combination of
properties of the best performers was superior to any of the
comparative materials tested which do not possess fluorochemical
oligomeric portions in their structures.
Examples 20-22
Using the Contact Angle Test Procedure, advancing and receding
contact angles were measured using n-hexadecane for three
fluorochemical oligomeric compounds of this invention. Advancing
contact angle measurement is an excellent predictor for water and
oil repellency, and receding contact angle is an excellent
predictor for soil resistance. Thus, any compound exhibiting high
advancing and receding contact angles would be expected to be an
excellent candidate as a textile, leather or carpet treatment.
Results are presented in TABLE 2.
TABLE 2 Adv. Contact Angle: Rec. Contact Angle: Ex. Fluorochemical
Additive Water n-C.sub.16 H.sub.34 Water n-C.sub.16 H.sub.34 20
(MeFOSEA).sub.4 --S-- 98.8 76.3 71.9 55.3 CH.sub.2 CH.sub.2
COOC.sub.18 H.sub.37 21 (MeFOSEA).sub.4 --S-- 99.1 77.9 69.1 56.7
CH.sub.2 CH.sub.2 COOC.sub.22 H.sub.43 22 (MeFOSEA).sub.4 --S--
99.1 77.5 68.0 59.6 CH.sub.2 CH.sub.2 COO-UNILIN .TM. 700
The data in TABLE 2 show that all three compounds exhibited very
good advancing and receding contact angles. Surprisingly, even the
compound with the very long alkyl group (i.e., derived from
UNILIN.TM. 700) demonstrated excellent contact angles against
n-hexadecane.
Example 23-25 and Comparative Examples C6-C8
In Examples 23-25, three fluorochemical oligomeric compounds of
this invention were incorporated at 1% into polypropylene and films
were made using the Film Extrusion Procedure. Each film was then
evaluated for release using the Peel Force Test Procedure, both
initially and after aging for 2 days at 49.degree. C. (120.degree.
F.). The release properties were compared to the properties
imparted to the polypropylene by two known fluorochemical polymer
melt additives (Comp. Ex. C6-C7) and when no polymer melt additive
was employed (Comp. Ex. C8).
Results are presented in TABLE 3.
TABLE 3 Peel Force, oz/in (N/m): Ex. Fluorochemical Additive Init.
Aged 23 (MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 COOC.sub.18 H.sub.37
5.2 12 24 (MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 COO-UNLIN .TM. 425
1.1 17 25 (MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 COO-UNLIN .TM. 700
1.5 16 C6 FC Oxazolidinone A 6.9 36 C7 [C.sub.8 F.sub.17 SO.sub.2
N(CH.sub.3)CH.sub.2 CH.sub.2 OOC].sub.2 -- 14 33 EMPOL .TM. 1008 C8
None 6.9 25
The data in TABLE 3 demonstrate that the three fluorochemical
oligomeric compounds clearly outperform the other two
fluorochemical polymer melt additives in imparting release
properties to polypropylene.
Examples 26-27 and Comparative Examples C9-C10
Fluorochemical oligomeric compounds were added to two different
thermoplastic resins, a polyethylene (PE6806) and a polyurethane
(PS440-200), webs were made according to the Melt-Blown Extrusion
Procedure, and the resulting webs were evaluated for repellency
using the Water Repellency Test and the Oil Repellency Test, The
melt-blown fabric were tested initially and after annealing at
120.degree. C. for 10 minutes. Also, the DOP Wetting Time Test was
run on the nonwoven webs.
Results from these evaluations are presented in TABLE 4.
TABLE 4 Water Rep.: Oil Rep.: Anne Anne DOP Wet. Ex. Polymer
Fluorochemical Additive Init. aled. Init. aled. Time 26 PE6806
(MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 COO-- 3 10 0 6 >2 days
UNILIN .TM. 700 C9 PE6806 None 2 2 0 0 immed. 27 PS440-
(TELOMER-A).sub.4 --S--CH.sub.2 CH.sub.2 COO-- 4 8 5 7 3.5 hr. 200
UNILIN .TM. 700 C10 PS440- None 2 3 0 0 immed. 200
The data in TABLE 4 show that incorporation of the fluorochemical
oligomeric compounds into either the polyethylene or the
polyurethane resin greatly enhanced water and oil resistance,
immediately and/or after annealing. Also, the DOP holdout imparted
by each of the fluorochemical oligomeric compounds was
excellent.
Example 28 and Comparative Example C11
Molded castings were made from a two-part, room
temperature-curable, thermoset epoxy resin system (3M
Scotch-Weld.TM. 2158 B/A Epoxy Adhesive Tube Kit) with and without
(MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 OOC-UNICID.TM. 700, an
alkylated fluorochemical oligomeric compound of this invention.
After curing, the castings were evaluated for water and oil
repellency.
In Example 28, 4.9 g of Part A, 4.9 g of Part B and 0.20 g of
(MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 OOC-UNICID.TM. 700 were
mixed together in an approximately 60 mm diameter aluminum weighing
pan. The sample was cured for 1 hour at 80.degree. C. and was left
overnight at room temperature. The Water Repellency Test and the
Oil Repellency Test were then run on the surface of the cured
casting; the same test liquids and rating scale were used as with
the nonwoven web repellency test, with the reported value
corresponding to the highest number test liquid for which a drop,
when placed on the surface of the film, would not spread.
In Comparative Example C11, the same epoxy resin preparation and
evaluation was run as described in Example 28, except that the
(MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 OOC-UNICID.TM. was omitted.
Results are presented in TABLE 5.
TABLE 5 Composition Water Oil Ex. of Epoxy Casting Repellency
Repellency 28 2158 + 2% (MeFOSEA).sub.4 -S-- 9 7 CH.sub.2 CH.sub.2
OOC-UNICID .TM. 700 C11 2158 only 1.5 0
The data in TABLE 5 show that the casting made from epoxy resin
having alkylated fluorochemical oligomeric compound added thereto
exhibited dramatically improved water and oil repellency relative
to the casting made from epoxy resin only.
Examples 29-30 and Comparative Examples C 12-C13
Molded castings were made from a one-part, moisture-curable,
thermoset polyurethane resin system (3M EC-5200 Marine Adhesive
Sealant) with and without (MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2
OOC-UNICID.TM. 700, an alkylated fluorochemical oligomeric compound
of this invention. After curing, the castings were evaluated for
water and oil repellency.
For each example, 4.9 g of EC-5200 sealant and 0.1 g of
(MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 OOC-UNICID.TM. 700 were
mixed together in two approximately 60 mm diameter aluminum
weighing pans, and the mixture was heated with a heat gun and
stirred until a homogeneous mixture resulted. For Example 29, the
resin system in the first pan was allowed to cure for 63 hours
under ambient conditions (roughly 50% relative humidity). For
Example 30, the resin system in the second pan was baked for 63
hours at 50.degree. C. above a pan of water. The Water Repellency
Test and the Oil Repellency Test were then run on the surface of
each cured resin; the same test liquids and rating scale were used
as with the nonwoven web repellency test, with the reported value
corresponding to the highest number test liquid for which a drop,
when placed on the surface of the film, would not spread.
In Comparative Examples C12-C13, the same moisture-cured
polyurethane resin preparation and evaluation was run as described
in Examples 29 and 30, respectively, except that the
(MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2 OOC-UNICID.TM. 700 was
omitted.
Results are presented in TABLE 6.
TABLE 6 Am- Composition bient Water Oil Ex. of Urethane Casting or
Bake Repel. Repel. 29 EC-5200 + 2.0% (MeFOSEA).sub.4 --S-- Am- 10 8
CH.sub.2 CH.sub.2 OOC-UNICID .TM. 700 bient C12 EC-5200 only Am- 2
0 bient 30 EC-5200 + 2.0% (MeFOSEA).sub.4 --S-- Bake 10 8 CH.sub.2
CH.sub.2 OOC-UNICID .TM. 700 C13 EC-5200 only Bake 7 1
The data in TABLE 6 show that the casting made from moisture-cured
polyurethane resin having (MeFOSEA).sub.4 --S--CH.sub.2 CH.sub.2
OOC-UNICID.TM. 700 added thereto exhibited dramatically improved
water and oil repellency to the casting made from moisture-cured
polyurethane resin only, cured either under ambient conditions or
baked.
Example 31-33 and Comparative Examples C14-C16
Using the Film Extrusion Procedure, films with an average thickness
of approximately 7 mils (0.3 mm) were cast from PP3545
polypropylene, with and without 3% polymer melt additive. Three
fluorochemical oligomeric compounds of this invention were
evaluated, along with two fluorochemical polymer melt additives
known in the art. The resulting films were evaluated for repellency
using the Water Repellency Test and the Oil Repellency Test.
Results are presented in TABLE 7.
TABLE 7 Water Oil Ex. Fluorochemical Additive Repellency Repellency
31 (MeFOSEA).sub.4 -S--CH.sub.2 CH.sub.2 COO-- 10 4.5 C.sub.18
H.sub.37 32 (MeFOSEA).sub.4 -S--CH.sub.2 CH.sub.2 COO-- 9 7
C.sub.22 H.sub.45 33 (MeFOSEA).sub.4 -S--CH.sub.2 CH.sub.2 COO- 10
7 UNILIN .TM. 700 C14 FC Oxazolidinone A 10 7 C15 [C.sub.8 F.sub.17
SO.sub.2 N(CH.sub.3)CH.sub.2 CH.sub.2 OOC].sub.2 - 9 2 EMPOL .TM.
1008 C16 -- 2 0
The data in TABLE 7 show that the films containing the
fluorochemical oligomeric compounds were comparable or superior in
repellency to the films containing the state-of-the-art
fluorochemical polymer melt additives.
Examples 34-38 and Comparative Examples C17-C19
This series of experiments was run to show the utility of
fluorochemical oligomeric compounds of this invention as polymer
melt additives for oily mist resistant electret filter media which
are treated by corona discharge.
In Comparative Example C17, PP3505 polypropylene with no polymer
melt additive was extruded as described in the Melt-Blown Extrusion
Procedure at a melt temperature of 297.degree. C. to form melt
blown microfiber web having a basis weight of 54 g/m.sup.2 and a
thickness of 0.79 mm. The fibers in the web had an average
effective fiber diameter of 8.0.+-.1.0 .mu.m. The web was annealed
at 149.degree. C. for 5 minutes and then corona charged using a
high voltage electric field provided between a corona source and a
ground electrode with a corona current of about 0.01 milliamp per
centimeter of corona source.
In Examples 34-38, nonwoven webs were prepared according to the
procedure of Comparative Example C17, except this time
fluorochemical compounds of this invention were added at about 1.1%
to the PP3505 polypropylene prior to extrusion. In Comparative
Examples C18-C19, nonwoven webs were prepared according to the
procedure of Comparative Example C17, except this time polymer melt
additives known in the art were added at about 1.1% to the PP3505
polypropylene prior to extrusion.
The % DOP penetration (% Pn), the pressure drop (.DELTA.P) and the
quality factor (QF) were determined for each sample using the DOP
Penetration and Pressure Drop Test. Results are presented in TABLE
8.
TABLE 8 QF .DELTA.P 1/(mm (mm of of Ex. Fluorochemical Additive %
Pn water) water) C17 -- 28.4 2.46 0.512 34 (TELOMER-A).sub.4 - 26.2
2.75 0.487 S--CH.sub.2 CH.sub.2 COO- UNILIN .TM. 700 35
(MeFOSEA).sub.4 -S--CH.sub.2 CH.sub.2 COO- 19.4 3.08 0.532 UNILIN
.TM. 700 36 (MeFOSEA).sub.4 -S--CH.sub.2 CH.sub.2 COO- 16.5 2.19
0.823 C.sub.18 H.sub.37 37 (MeFOSEA).sub.4 -S--CH.sub.2 CH.sub.2
OOC- 25.9 1.89 0.715 UNICID .TM. 700 38 (MeFOSEA).sub.4
-S--CH.sub.2 CH.sub.2 COO- 23.6 1.87 0.772 CH.sub.2 CH.sub.2
N(CH.sub.3)SO.sub.2 C.sub.8 F.sub.17 C18 FC Oxazolidinone A 22.4
2.13 0.723 C19 [C.sub.8 F.sub.17 SO.sub.2 N(CH.sub.3)CH.sub.2
CH.sub.2 OOC].sub.2 - 27.1 2.56 0.510 EMPOL .TM. 1008
The data in TABLE 8 show that improved overall performance is
realized when certain fluorochemical oligomeric compounds are
employed as compared to the comparative polymer melt additives or
no melt additive at all.
Examples 39-43 and Comparative Examples C20-C22
This series of experiments was run to show the utility of
fluorochemical oligomeric compounds of this invention as polymer
melt additives for oily mist resistant electret filter media
charged using jets of water.
In Comparative Example C20, PP3505 polypropylene with no polymer
melt additive was extruded as described in the Melt-Blown Extrusion
Procedure at a melt temperature of 297.degree. C. to form melt
blown microfiber web having a basis weight of 54 g/m.sup.2 and a
thickness of 0.79 mm. The fibers in the web had an average
effective fiber diameter of 8.0.+-.1.0 .mu.m. The web was annealed
at 149.degree. C. for 5 minutes. Hydrocharging was performed by
passing the web sample at a rate of 5 cm/second across a vacuum
slot 25.4 cm long and 0.5 cm wide powered by a Dayton 2Z974B.TM.
vacuum cleaner (Dayton Electric, Chicago). A pair of Spraying
Systems Teejet 9501.TM. sprayer nozzles was mounted 10 cm apart and
centered 7 cm above the vacuum slot. Deionized water was sprayed
through the nozzles with a hydrostatic pressure of about 90 psi
(620 kPa). The web is passed through the spray on one side then
inverted and passed through a second time such that both sides of
the web were sprayed. The spray was turned off and the web passed
across a vacuum slot with no water spray such that each side is
exposed to the vacuum to remove excess water. The web was then hung
to dry at ambient conditions.
In Examples 39-43, nonwoven webs were prepared according to the
procedure of Comparative Example C20, except this time
fluorochemical compounds of this invention were added at about 1.1%
to the PP3505 polypropylene prior to extrusion. In Comparative
Examples C21-C22, nonwoven webs were prepared according to the
procedure of Comparative Example C20, except this time polymer melt
additives known in the art were added at about 1.1% to the PP3505
polypropylene prior to extrusion.
The % DOP penetration (% Pn), the pressure drop (.DELTA.P) and the
quality factor (QF) were determined for each sample using the DOP
Penetration and Pressure Drop Test. Results are presented in TABLE
9.
TABLE 9 Ex. Fluorochemical Additive % Pn .DELTA.P QF C20 -- 12.2
2.31 0.911 39 (TELOMER-A).sub.4 - 3.30 2.85 1.197 S--CH.sub.2
CH.sub.2 COO- UNILIN .TM. 700 40 (MeFOSEA).sub.4 -S--CH.sub.2
CH.sub.2 COO- 1.60 3.31 1.249 UNILIN .TM. 700 41 (MeFOSEA).sub.4
-S--CH.sub.2 CH.sub.2 COO- 7.24 1.97 1.333 C.sub.18 H.sub.37 42
(MeFOSEA).sub.4 -S--CH.sub.2 CH.sub.2 OOC- 6.40 1.84 1.494 UNICID
.TM. 700 43 (MeFOSEA).sub.4 -S--CH.sub.2 CH.sub.2 COO- 11.00 1.77
1.247 CH.sub.2 CH.sub.2 N(CH.sub.3)SO.sub.2 C.sub.8 F.sub.17 C21 FC
Oxazolidinone A 3.98 2.27 1.472 C22 [C.sub.8 F.sub.17 SO.sub.2
N(CH.sub.3)CH.sub.2 CH.sub.2 OOC].sub.2 - 9.90 2.96 0.781 EMPOL
.TM. 1008
The data in TABLE 9 show the fluorochemical oligomeric compounds of
this invention generally perform well in this application.
Generally Quality Factors (QF), for flat media, in excess of 0.3
cannot be achieved in any way except through electret
enhancement.
* * * * *